diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 33820d04..6c5c95cd 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -27,7 +27,7 @@ repos:
         language: pygrep
         entry: \b([A-Za-z]+)[ \t]+\1\b
         types: [text]
-        exclude: ^tests/data/
+        exclude: ^(tests/data/|dataretrieval/codes/_county_table\.py$)
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
     rev: v0.16.5
diff --git a/CONTEXT.md b/CONTEXT.md
index f76a9f7e..625b9a1a 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -143,6 +143,36 @@ a service names a thing `site-types` or `site_type_code`, that is its vocabulary
 and is reproduced rather than translated. Prose that is not about one particular
 adapter says *monitoring location*.
 
+**State** — A US state, the District of Columbia, or one of the five
+territories, as the place a monitoring location is in.
+
+*Domain term.* The services spell it differently: Water Data `state_name`
+(`"Wisconsin"`) and `state_code` (`"55"`), the Water Data statistics service
+`state_code` (`"US:55"`), NGWMN `state_name` on `sites` but a postal `state`
+(`"WI"`) on `providers`, NWDC `stateCd:WI`, WQP `statecode`, NWIS `stateCd`.
+Each adapter keeps those parameters. Where an adapter also takes `state`, that is
+a *unified argument* and not a service's spelling.
+
+**County** — A county or county equivalent (parish, borough, census area,
+independent city, municipio, Connecticut planning region) within a state.
+
+*Domain term.* A county's three-digit code repeats across states, so it is
+identified by state and county together, and the services spell the pair
+differently: Water Data `state_code` + `county_code` (`"55"` + `"025"`) or
+`county_name` (`"Dane County"`), the statistics service one `county_code`
+(`"US:55:025"`), NGWMN `state_name` + `county_name`, NWDC `countyCd:55025`, WQP
+`countycode`, NWIS `countyCd`. Where an adapter also takes `county`, that is a
+unified argument.
+
+**Unified argument** — A getter argument named by the package for a domain
+concept, accepting every common spelling of it and sending each service the one
+it filters on: `state` (a name, postal code, or FIPS code) and `county` (a
+FIPS code, or a name with its state). It is added beside the service's own
+parameters, never in their place; the rule is ADR 0013's.
+
+*Core term.* The argument names are the package's; the conversion tables are in
+`dataretrieval.codes`.
+
 **Metadata** — The second half of every getter's return: the request URL, the
 elapsed time, and the response headers. Describes the *retrieval*, not the data.
 
diff --git a/NEWS.md b/NEWS.md
index 3b6b389a..f20d8822 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,5 @@
+**10/01/2026:** **New:** a `county` argument, like `state`, on `waterdata.get_monitoring_locations()`, `waterdata.get_combined_metadata()`, `waterdata.get_stats_por()`, `waterdata.get_stats_date_range()`, `ngwmn.get_sites()`, and `nwdc.get_wateruse()`. It accepts a five-digit FIPS code (`"55025"` or `55025`), the statistics service's `"US:55:025"`, or a name or three-digit code with its state (`county="Dane", state="WI"`), and sends each service the fields it filters on: Water Data `state_code` + `county_code`, statistics `county_code="US:55:025"`, NGWMN `state_name` + `county_name`, NWDC `countyCd:55025`. With `county`, `state` names the counties' state rather than filtering separately. `dataretrieval.codes.to_county()` exposes the conversion; its table is the Water Data `counties` collection for the 50 states, DC, and the territories, and a live test compares the two. The native `county_code` / `county_name` parameters are unchanged, and passing one with `county` raises `ValueError`. Counties in several states are sent to the Water Data location collections as a CQL `filter` OR-ing (state, county) pairs, so they cannot be combined with your own `filter`; `ngwmn.get_sites()` takes counties from one state per call, and raises for Connecticut, whose NGWMN sites are still filed under the counties the state replaced with planning regions in 2022 (pass `county_name="Hartford County"` instead). WQP and legacy NWIS are unchanged, as they are for `state`. **Bug fix:** `ngwmn.get_sites(county_name=[...])` with more than one name returned no rows: NGWMN matches nothing for a comma-joined `county_name`. Multi-value `sites` filters are now POSTed as CQL2, as the Water Data location collections' are. **Behavior change:** `nwdc.get_wateruse(state=..., county=...)` no longer raises for naming two locations; the state qualifies the county, and a county outside it raises. An unknown county such as Connecticut's retired `"09003"` now raises locally instead of HTTP 400.
+
 **10/01/2026:** **Behavior change:** the numeric columns of the `waterdata` OGC getters and `ngwmn` — `value`, `altitude`, `drainage_area`, and the other measurement columns — are always `float64`. They were `int64` whenever every value in a response happened to be whole, so the same column changed dtype between calls, breaking concatenation, schema checks, and typed stores (#428). **Behavior change:** a value in a numeric or datetime column that cannot be parsed still becomes `NaN`/`NaT`, but now emits a `UserWarning` naming the column and the count, so a parse failure is distinguishable from a missing value. Repeat the call with `convert_type=False` to see the raw values. Expect it from `waterdata.get_monitoring_locations()`: its `construction_date` holds partial dates (`1925`, `194805`, `19100000`) that a datetime column cannot represent, and they were already being dropped without notice — 7,306 of 24,089 values in a query for Maryland groundwater sites.
 
 **10/01/2026:** **Bug fix:** `waterdata.get_nearest_continuous` turned a missing target (`NaT`, `None`, `NaN`, or `""`) into a `(time >= 'nan' AND time <= 'nan')` clause and sent it to the service, including when only one entry of a list was missing. It now raises `ValueError` before any request, naming how many targets are missing and the position of the first. Targets pandas cannot parse now raise a `ValueError` that names `targets`, rather than pandas' message, which named no argument and suggested a `format=` the getter does not accept. **Bug fix:** the same getter's `window` was not validated: a missing window (`None`, `'NaT'`) failed with an `AttributeError` while the filter was built, and a negative one (`'-PT5M'`) inverted every bound, so the query matched nothing and returned an empty frame indistinguishable from a gap in the data. Both now raise `ValueError` naming `window`; a zero window remains an exact-match query. **Behavior change:** a bare-number `window` now raises `TypeError`; pandas read `window=450` as 450 nanoseconds, so it matched almost nothing. Pass a duration such as `window='PT450S'`. Numeric `targets` raise `TypeError` for the same reason: `targets=[1.5e9]` meant as epoch seconds was read as 1970-01-01T00:00:01.5Z. **Behavior change:** calls that previously sent a malformed filter now fail locally, so a caller passing targets with gaps must drop or fill them first.
diff --git a/dataretrieval/codes/__init__.py b/dataretrieval/codes/__init__.py
index d14aa942..bd9469e1 100644
--- a/dataretrieval/codes/__init__.py
+++ b/dataretrieval/codes/__init__.py
@@ -1,8 +1,10 @@
-"""Facade over the ``states`` and ``timezones`` lookup tables.
+"""Facade over the ``states``, ``counties``, and ``timezones`` lookup tables.
 
-Re-exports the state code maps, their normalizers (``to_state``,
-``apply_state``), and the ``tz`` UTC-offset map.
+Re-exports the state code maps and their normalizers (``to_state``,
+``apply_state``), the county map and its normalizers (``to_county``,
+``apply_county``), and the ``tz`` UTC-offset map.
 """
 
+from .counties import *
 from .states import *
 from .timezones import *
diff --git a/dataretrieval/codes/_county_table.py b/dataretrieval/codes/_county_table.py
new file mode 100644
index 00000000..7e173ecd
--- /dev/null
+++ b/dataretrieval/codes/_county_table.py
@@ -0,0 +1,3253 @@
+"""The county table behind :mod:`dataretrieval.codes.counties`: data only.
+
+Generated from the Water Data ``counties`` collection; see
+``tests/counties_test.py::test_the_table_matches_the_water_data_counties_collection``
+for how to regenerate it. Kept apart from the code so the doubled-word check,
+which a name like "Walla Walla County" trips, can skip this file alone.
+"""
+
+#: Five-digit FIPS code -> county name, as the Water Data ``counties``
+#: collection spells it (snapshot 2026-10-01, ``country_code=US``, without its
+#: ``000`` "Unspecified" placeholders and the minor outlying islands that
+#: :mod:`~dataretrieval.codes.states` does not cover).
+counties: dict[str, str] = {
+    "01001": "Autauga County",
+    "01003": "Baldwin County",
+    "01005": "Barbour County",
+    "01007": "Bibb County",
+    "01009": "Blount County",
+    "01011": "Bullock County",
+    "01013": "Butler County",
+    "01015": "Calhoun County",
+    "01017": "Chambers County",
+    "01019": "Cherokee County",
+    "01021": "Chilton County",
+    "01023": "Choctaw County",
+    "01025": "Clarke County",
+    "01027": "Clay County",
+    "01029": "Cleburne County",
+    "01031": "Coffee County",
+    "01033": "Colbert County",
+    "01035": "Conecuh County",
+    "01037": "Coosa County",
+    "01039": "Covington County",
+    "01041": "Crenshaw County",
+    "01043": "Cullman County",
+    "01045": "Dale County",
+    "01047": "Dallas County",
+    "01049": "DeKalb County",
+    "01051": "Elmore County",
+    "01053": "Escambia County",
+    "01055": "Etowah County",
+    "01057": "Fayette County",
+    "01059": "Franklin County",
+    "01061": "Geneva County",
+    "01063": "Greene County",
+    "01065": "Hale County",
+    "01067": "Henry County",
+    "01069": "Houston County",
+    "01071": "Jackson County",
+    "01073": "Jefferson County",
+    "01075": "Lamar County",
+    "01077": "Lauderdale County",
+    "01079": "Lawrence County",
+    "01081": "Lee County",
+    "01083": "Limestone County",
+    "01085": "Lowndes County",
+    "01087": "Macon County",
+    "01089": "Madison County",
+    "01091": "Marengo County",
+    "01093": "Marion County",
+    "01095": "Marshall County",
+    "01097": "Mobile County",
+    "01099": "Monroe County",
+    "01101": "Montgomery County",
+    "01103": "Morgan County",
+    "01105": "Perry County",
+    "01107": "Pickens County",
+    "01109": "Pike County",
+    "01111": "Randolph County",
+    "01113": "Russell County",
+    "01115": "St. Clair County",
+    "01117": "Shelby County",
+    "01119": "Sumter County",
+    "01121": "Talladega County",
+    "01123": "Tallapoosa County",
+    "01125": "Tuscaloosa County",
+    "01127": "Walker County",
+    "01129": "Washington County",
+    "01131": "Wilcox County",
+    "01133": "Winston County",
+    "02013": "Aleutians East Borough",
+    "02016": "Aleutians West Census Area",
+    "02020": "Anchorage Municipality",
+    "02050": "Bethel Census Area",
+    "02060": "Bristol Bay Borough",
+    "02063": "Chugach Census Area",
+    "02066": "Copper River Census Area",
+    "02068": "Denali Borough",
+    "02070": "Dillingham Census Area",
+    "02090": "Fairbanks North Star Borough",
+    "02100": "Haines Borough",
+    "02105": "Hoonah-Angoon Census Area",
+    "02110": "Juneau City and Borough",
+    "02122": "Kenai Peninsula Borough",
+    "02130": "Ketchikan Gateway Borough",
+    "02150": "Kodiak Island Borough",
+    "02158": "Kusilvak Census Area",
+    "02164": "Lake and Peninsula Borough",
+    "02170": "Matanuska-Susitna Borough",
+    "02180": "Nome Census Area",
+    "02185": "North Slope Borough",
+    "02188": "Northwest Arctic Borough",
+    "02195": "Petersburg Borough",
+    "02198": "Prince of Wales-Hyder Census Area",
+    "02220": "City and Borough of Sitka",
+    "02230": "Skagway Municipality",
+    "02240": "Southeast Fairbanks Census Area",
+    "02275": "Wrangell City and Borough",
+    "02282": "Yakutat City and Borough",
+    "02290": "Yukon-Koyukuk Census Area",
+    "04001": "Apache County",
+    "04003": "Cochise County",
+    "04005": "Coconino County",
+    "04007": "Gila County",
+    "04009": "Graham County",
+    "04011": "Greenlee County",
+    "04012": "La Paz County",
+    "04013": "Maricopa County",
+    "04015": "Mohave County",
+    "04017": "Navajo County",
+    "04019": "Pima County",
+    "04021": "Pinal County",
+    "04023": "Santa Cruz County",
+    "04025": "Yavapai County",
+    "04027": "Yuma County",
+    "05001": "Arkansas County",
+    "05003": "Ashley County",
+    "05005": "Baxter County",
+    "05007": "Benton County",
+    "05009": "Boone County",
+    "05011": "Bradley County",
+    "05013": "Calhoun County",
+    "05015": "Carroll County",
+    "05017": "Chicot County",
+    "05019": "Clark County",
+    "05021": "Clay County",
+    "05023": "Cleburne County",
+    "05025": "Cleveland County",
+    "05027": "Columbia County",
+    "05029": "Conway County",
+    "05031": "Craighead County",
+    "05033": "Crawford County",
+    "05035": "Crittenden County",
+    "05037": "Cross County",
+    "05039": "Dallas County",
+    "05041": "Desha County",
+    "05043": "Drew County",
+    "05045": "Faulkner County",
+    "05047": "Franklin County",
+    "05049": "Fulton County",
+    "05051": "Garland County",
+    "05053": "Grant County",
+    "05055": "Greene County",
+    "05057": "Hempstead County",
+    "05059": "Hot Spring County",
+    "05061": "Howard County",
+    "05063": "Independence County",
+    "05065": "Izard County",
+    "05067": "Jackson County",
+    "05069": "Jefferson County",
+    "05071": "Johnson County",
+    "05073": "Lafayette County",
+    "05075": "Lawrence County",
+    "05077": "Lee County",
+    "05079": "Lincoln County",
+    "05081": "Little River County",
+    "05083": "Logan County",
+    "05085": "Lonoke County",
+    "05087": "Madison County",
+    "05089": "Marion County",
+    "05091": "Miller County",
+    "05093": "Mississippi County",
+    "05095": "Monroe County",
+    "05097": "Montgomery County",
+    "05099": "Nevada County",
+    "05101": "Newton County",
+    "05103": "Ouachita County",
+    "05105": "Perry County",
+    "05107": "Phillips County",
+    "05109": "Pike County",
+    "05111": "Poinsett County",
+    "05113": "Polk County",
+    "05115": "Pope County",
+    "05117": "Prairie County",
+    "05119": "Pulaski County",
+    "05121": "Randolph County",
+    "05123": "St. Francis County",
+    "05125": "Saline County",
+    "05127": "Scott County",
+    "05129": "Searcy County",
+    "05131": "Sebastian County",
+    "05133": "Sevier County",
+    "05135": "Sharp County",
+    "05137": "Stone County",
+    "05139": "Union County",
+    "05141": "Van Buren County",
+    "05143": "Washington County",
+    "05145": "White County",
+    "05147": "Woodruff County",
+    "05149": "Yell County",
+    "06001": "Alameda County",
+    "06003": "Alpine County",
+    "06005": "Amador County",
+    "06007": "Butte County",
+    "06009": "Calaveras County",
+    "06011": "Colusa County",
+    "06013": "Contra Costa County",
+    "06015": "Del Norte County",
+    "06017": "El Dorado County",
+    "06019": "Fresno County",
+    "06021": "Glenn County",
+    "06023": "Humboldt County",
+    "06025": "Imperial County",
+    "06027": "Inyo County",
+    "06029": "Kern County",
+    "06031": "Kings County",
+    "06033": "Lake County",
+    "06035": "Lassen County",
+    "06037": "Los Angeles County",
+    "06039": "Madera County",
+    "06041": "Marin County",
+    "06043": "Mariposa County",
+    "06045": "Mendocino County",
+    "06047": "Merced County",
+    "06049": "Modoc County",
+    "06051": "Mono County",
+    "06053": "Monterey County",
+    "06055": "Napa County",
+    "06057": "Nevada County",
+    "06059": "Orange County",
+    "06061": "Placer County",
+    "06063": "Plumas County",
+    "06065": "Riverside County",
+    "06067": "Sacramento County",
+    "06069": "San Benito County",
+    "06071": "San Bernardino County",
+    "06073": "San Diego County",
+    "06075": "San Francisco County",
+    "06077": "San Joaquin County",
+    "06079": "San Luis Obispo County",
+    "06081": "San Mateo County",
+    "06083": "Santa Barbara County",
+    "06085": "Santa Clara County",
+    "06087": "Santa Cruz County",
+    "06089": "Shasta County",
+    "06091": "Sierra County",
+    "06093": "Siskiyou County",
+    "06095": "Solano County",
+    "06097": "Sonoma County",
+    "06099": "Stanislaus County",
+    "06101": "Sutter County",
+    "06103": "Tehama County",
+    "06105": "Trinity County",
+    "06107": "Tulare County",
+    "06109": "Tuolumne County",
+    "06111": "Ventura County",
+    "06113": "Yolo County",
+    "06115": "Yuba County",
+    "08001": "Adams County",
+    "08003": "Alamosa County",
+    "08005": "Arapahoe County",
+    "08007": "Archuleta County",
+    "08009": "Baca County",
+    "08011": "Bent County",
+    "08013": "Boulder County",
+    "08014": "Broomfield County",
+    "08015": "Chaffee County",
+    "08017": "Cheyenne County",
+    "08019": "Clear Creek County",
+    "08021": "Conejos County",
+    "08023": "Costilla County",
+    "08025": "Crowley County",
+    "08027": "Custer County",
+    "08029": "Delta County",
+    "08031": "Denver County",
+    "08033": "Dolores County",
+    "08035": "Douglas County",
+    "08037": "Eagle County",
+    "08039": "Elbert County",
+    "08041": "El Paso County",
+    "08043": "Fremont County",
+    "08045": "Garfield County",
+    "08047": "Gilpin County",
+    "08049": "Grand County",
+    "08051": "Gunnison County",
+    "08053": "Hinsdale County",
+    "08055": "Huerfano County",
+    "08057": "Jackson County",
+    "08059": "Jefferson County",
+    "08061": "Kiowa County",
+    "08063": "Kit Carson County",
+    "08065": "Lake County",
+    "08067": "La Plata County",
+    "08069": "Larimer County",
+    "08071": "Las Animas County",
+    "08073": "Lincoln County",
+    "08075": "Logan County",
+    "08077": "Mesa County",
+    "08079": "Mineral County",
+    "08081": "Moffat County",
+    "08083": "Montezuma County",
+    "08085": "Montrose County",
+    "08087": "Morgan County",
+    "08089": "Otero County",
+    "08091": "Ouray County",
+    "08093": "Park County",
+    "08095": "Phillips County",
+    "08097": "Pitkin County",
+    "08099": "Prowers County",
+    "08101": "Pueblo County",
+    "08103": "Rio Blanco County",
+    "08105": "Rio Grande County",
+    "08107": "Routt County",
+    "08109": "Saguache County",
+    "08111": "San Juan County",
+    "08113": "San Miguel County",
+    "08115": "Sedgwick County",
+    "08117": "Summit County",
+    "08119": "Teller County",
+    "08121": "Washington County",
+    "08123": "Weld County",
+    "08125": "Yuma County",
+    "09110": "Capitol Planning Region",
+    "09120": "Greater Bridgeport Planning Region",
+    "09130": "Lower Connecticut River Valley Planning Region",
+    "09140": "Naugatuck Valley Planning Region",
+    "09150": "Northeastern Connecticut Planning Region",
+    "09160": "Northwest Hills Planning Region",
+    "09170": "South Central Connecticut Planning Region",
+    "09180": "Southeastern Connecticut Planning Region",
+    "09190": "Western Connecticut Planning Region",
+    "10001": "Kent County",
+    "10003": "New Castle County",
+    "10005": "Sussex County",
+    "11001": "District of Columbia",
+    "12001": "Alachua County",
+    "12003": "Baker County",
+    "12005": "Bay County",
+    "12007": "Bradford County",
+    "12009": "Brevard County",
+    "12011": "Broward County",
+    "12013": "Calhoun County",
+    "12015": "Charlotte County",
+    "12017": "Citrus County",
+    "12019": "Clay County",
+    "12021": "Collier County",
+    "12023": "Columbia County",
+    "12027": "DeSoto County",
+    "12029": "Dixie County",
+    "12031": "Duval County",
+    "12033": "Escambia County",
+    "12035": "Flagler County",
+    "12037": "Franklin County",
+    "12039": "Gadsden County",
+    "12041": "Gilchrist County",
+    "12043": "Glades County",
+    "12045": "Gulf County",
+    "12047": "Hamilton County",
+    "12049": "Hardee County",
+    "12051": "Hendry County",
+    "12053": "Hernando County",
+    "12055": "Highlands County",
+    "12057": "Hillsborough County",
+    "12059": "Holmes County",
+    "12061": "Indian River County",
+    "12063": "Jackson County",
+    "12065": "Jefferson County",
+    "12067": "Lafayette County",
+    "12069": "Lake County",
+    "12071": "Lee County",
+    "12073": "Leon County",
+    "12075": "Levy County",
+    "12077": "Liberty County",
+    "12079": "Madison County",
+    "12081": "Manatee County",
+    "12083": "Marion County",
+    "12085": "Martin County",
+    "12086": "Miami-Dade County",
+    "12087": "Monroe County",
+    "12089": "Nassau County",
+    "12091": "Okaloosa County",
+    "12093": "Okeechobee County",
+    "12095": "Orange County",
+    "12097": "Osceola County",
+    "12099": "Palm Beach County",
+    "12101": "Pasco County",
+    "12103": "Pinellas County",
+    "12105": "Polk County",
+    "12107": "Putnam County",
+    "12109": "St. Johns County",
+    "12111": "St. Lucie County",
+    "12113": "Santa Rosa County",
+    "12115": "Sarasota County",
+    "12117": "Seminole County",
+    "12119": "Sumter County",
+    "12121": "Suwannee County",
+    "12123": "Taylor County",
+    "12125": "Union County",
+    "12127": "Volusia County",
+    "12129": "Wakulla County",
+    "12131": "Walton County",
+    "12133": "Washington County",
+    "13001": "Appling County",
+    "13003": "Atkinson County",
+    "13005": "Bacon County",
+    "13007": "Baker County",
+    "13009": "Baldwin County",
+    "13011": "Banks County",
+    "13013": "Barrow County",
+    "13015": "Bartow County",
+    "13017": "Ben Hill County",
+    "13019": "Berrien County",
+    "13021": "Bibb County",
+    "13023": "Bleckley County",
+    "13025": "Brantley County",
+    "13027": "Brooks County",
+    "13029": "Bryan County",
+    "13031": "Bulloch County",
+    "13033": "Burke County",
+    "13035": "Butts County",
+    "13037": "Calhoun County",
+    "13039": "Camden County",
+    "13043": "Candler County",
+    "13045": "Carroll County",
+    "13047": "Catoosa County",
+    "13049": "Charlton County",
+    "13051": "Chatham County",
+    "13053": "Chattahoochee County",
+    "13055": "Chattooga County",
+    "13057": "Cherokee County",
+    "13059": "Clarke County",
+    "13061": "Clay County",
+    "13063": "Clayton County",
+    "13065": "Clinch County",
+    "13067": "Cobb County",
+    "13069": "Coffee County",
+    "13071": "Colquitt County",
+    "13073": "Columbia County",
+    "13075": "Cook County",
+    "13077": "Coweta County",
+    "13079": "Crawford County",
+    "13081": "Crisp County",
+    "13083": "Dade County",
+    "13085": "Dawson County",
+    "13087": "Decatur County",
+    "13089": "DeKalb County",
+    "13091": "Dodge County",
+    "13093": "Dooly County",
+    "13095": "Dougherty County",
+    "13097": "Douglas County",
+    "13099": "Early County",
+    "13101": "Echols County",
+    "13103": "Effingham County",
+    "13105": "Elbert County",
+    "13107": "Emanuel County",
+    "13109": "Evans County",
+    "13111": "Fannin County",
+    "13113": "Fayette County",
+    "13115": "Floyd County",
+    "13117": "Forsyth County",
+    "13119": "Franklin County",
+    "13121": "Fulton County",
+    "13123": "Gilmer County",
+    "13125": "Glascock County",
+    "13127": "Glynn County",
+    "13129": "Gordon County",
+    "13131": "Grady County",
+    "13133": "Greene County",
+    "13135": "Gwinnett County",
+    "13137": "Habersham County",
+    "13139": "Hall County",
+    "13141": "Hancock County",
+    "13143": "Haralson County",
+    "13145": "Harris County",
+    "13147": "Hart County",
+    "13149": "Heard County",
+    "13151": "Henry County",
+    "13153": "Houston County",
+    "13155": "Irwin County",
+    "13157": "Jackson County",
+    "13159": "Jasper County",
+    "13161": "Jeff Davis County",
+    "13163": "Jefferson County",
+    "13165": "Jenkins County",
+    "13167": "Johnson County",
+    "13169": "Jones County",
+    "13171": "Lamar County",
+    "13173": "Lanier County",
+    "13175": "Laurens County",
+    "13177": "Lee County",
+    "13179": "Liberty County",
+    "13181": "Lincoln County",
+    "13183": "Long County",
+    "13185": "Lowndes County",
+    "13187": "Lumpkin County",
+    "13189": "McDuffie County",
+    "13191": "McIntosh County",
+    "13193": "Macon County",
+    "13195": "Madison County",
+    "13197": "Marion County",
+    "13199": "Meriwether County",
+    "13201": "Miller County",
+    "13205": "Mitchell County",
+    "13207": "Monroe County",
+    "13209": "Montgomery County",
+    "13211": "Morgan County",
+    "13213": "Murray County",
+    "13215": "Muscogee County",
+    "13217": "Newton County",
+    "13219": "Oconee County",
+    "13221": "Oglethorpe County",
+    "13223": "Paulding County",
+    "13225": "Peach County",
+    "13227": "Pickens County",
+    "13229": "Pierce County",
+    "13231": "Pike County",
+    "13233": "Polk County",
+    "13235": "Pulaski County",
+    "13237": "Putnam County",
+    "13239": "Quitman County",
+    "13241": "Rabun County",
+    "13243": "Randolph County",
+    "13245": "Richmond County",
+    "13247": "Rockdale County",
+    "13249": "Schley County",
+    "13251": "Screven County",
+    "13253": "Seminole County",
+    "13255": "Spalding County",
+    "13257": "Stephens County",
+    "13259": "Stewart County",
+    "13261": "Sumter County",
+    "13263": "Talbot County",
+    "13265": "Taliaferro County",
+    "13267": "Tattnall County",
+    "13269": "Taylor County",
+    "13271": "Telfair County",
+    "13273": "Terrell County",
+    "13275": "Thomas County",
+    "13277": "Tift County",
+    "13279": "Toombs County",
+    "13281": "Towns County",
+    "13283": "Treutlen County",
+    "13285": "Troup County",
+    "13287": "Turner County",
+    "13289": "Twiggs County",
+    "13291": "Union County",
+    "13293": "Upson County",
+    "13295": "Walker County",
+    "13297": "Walton County",
+    "13299": "Ware County",
+    "13301": "Warren County",
+    "13303": "Washington County",
+    "13305": "Wayne County",
+    "13307": "Webster County",
+    "13309": "Wheeler County",
+    "13311": "White County",
+    "13313": "Whitfield County",
+    "13315": "Wilcox County",
+    "13317": "Wilkes County",
+    "13319": "Wilkinson County",
+    "13321": "Worth County",
+    "15001": "Hawaii County",
+    "15003": "Honolulu County",
+    "15005": "Kalawao County",
+    "15007": "Kauai County",
+    "15009": "Maui County",
+    "16001": "Ada County",
+    "16003": "Adams County",
+    "16005": "Bannock County",
+    "16007": "Bear Lake County",
+    "16009": "Benewah County",
+    "16011": "Bingham County",
+    "16013": "Blaine County",
+    "16015": "Boise County",
+    "16017": "Bonner County",
+    "16019": "Bonneville County",
+    "16021": "Boundary County",
+    "16023": "Butte County",
+    "16025": "Camas County",
+    "16027": "Canyon County",
+    "16029": "Caribou County",
+    "16031": "Cassia County",
+    "16033": "Clark County",
+    "16035": "Clearwater County",
+    "16037": "Custer County",
+    "16039": "Elmore County",
+    "16041": "Franklin County",
+    "16043": "Fremont County",
+    "16045": "Gem County",
+    "16047": "Gooding County",
+    "16049": "Idaho County",
+    "16051": "Jefferson County",
+    "16053": "Jerome County",
+    "16055": "Kootenai County",
+    "16057": "Latah County",
+    "16059": "Lemhi County",
+    "16061": "Lewis County",
+    "16063": "Lincoln County",
+    "16065": "Madison County",
+    "16067": "Minidoka County",
+    "16069": "Nez Perce County",
+    "16071": "Oneida County",
+    "16073": "Owyhee County",
+    "16075": "Payette County",
+    "16077": "Power County",
+    "16079": "Shoshone County",
+    "16081": "Teton County",
+    "16083": "Twin Falls County",
+    "16085": "Valley County",
+    "16087": "Washington County",
+    "17001": "Adams County",
+    "17003": "Alexander County",
+    "17005": "Bond County",
+    "17007": "Boone County",
+    "17009": "Brown County",
+    "17011": "Bureau County",
+    "17013": "Calhoun County",
+    "17015": "Carroll County",
+    "17017": "Cass County",
+    "17019": "Champaign County",
+    "17021": "Christian County",
+    "17023": "Clark County",
+    "17025": "Clay County",
+    "17027": "Clinton County",
+    "17029": "Coles County",
+    "17031": "Cook County",
+    "17033": "Crawford County",
+    "17035": "Cumberland County",
+    "17037": "DeKalb County",
+    "17039": "DeWitt County",
+    "17041": "Douglas County",
+    "17043": "DuPage County",
+    "17045": "Edgar County",
+    "17047": "Edwards County",
+    "17049": "Effingham County",
+    "17051": "Fayette County",
+    "17053": "Ford County",
+    "17055": "Franklin County",
+    "17057": "Fulton County",
+    "17059": "Gallatin County",
+    "17061": "Greene County",
+    "17063": "Grundy County",
+    "17065": "Hamilton County",
+    "17067": "Hancock County",
+    "17069": "Hardin County",
+    "17071": "Henderson County",
+    "17073": "Henry County",
+    "17075": "Iroquois County",
+    "17077": "Jackson County",
+    "17079": "Jasper County",
+    "17081": "Jefferson County",
+    "17083": "Jersey County",
+    "17085": "Jo Daviess County",
+    "17087": "Johnson County",
+    "17089": "Kane County",
+    "17091": "Kankakee County",
+    "17093": "Kendall County",
+    "17095": "Knox County",
+    "17097": "Lake County",
+    "17099": "LaSalle County",
+    "17101": "Lawrence County",
+    "17103": "Lee County",
+    "17105": "Livingston County",
+    "17107": "Logan County",
+    "17109": "McDonough County",
+    "17111": "McHenry County",
+    "17113": "McLean County",
+    "17115": "Macon County",
+    "17117": "Macoupin County",
+    "17119": "Madison County",
+    "17121": "Marion County",
+    "17123": "Marshall County",
+    "17125": "Mason County",
+    "17127": "Massac County",
+    "17129": "Menard County",
+    "17131": "Mercer County",
+    "17133": "Monroe County",
+    "17135": "Montgomery County",
+    "17137": "Morgan County",
+    "17139": "Moultrie County",
+    "17141": "Ogle County",
+    "17143": "Peoria County",
+    "17145": "Perry County",
+    "17147": "Piatt County",
+    "17149": "Pike County",
+    "17151": "Pope County",
+    "17153": "Pulaski County",
+    "17155": "Putnam County",
+    "17157": "Randolph County",
+    "17159": "Richland County",
+    "17161": "Rock Island County",
+    "17163": "St. Clair County",
+    "17165": "Saline County",
+    "17167": "Sangamon County",
+    "17169": "Schuyler County",
+    "17171": "Scott County",
+    "17173": "Shelby County",
+    "17175": "Stark County",
+    "17177": "Stephenson County",
+    "17179": "Tazewell County",
+    "17181": "Union County",
+    "17183": "Vermilion County",
+    "17185": "Wabash County",
+    "17187": "Warren County",
+    "17189": "Washington County",
+    "17191": "Wayne County",
+    "17193": "White County",
+    "17195": "Whiteside County",
+    "17197": "Will County",
+    "17199": "Williamson County",
+    "17201": "Winnebago County",
+    "17203": "Woodford County",
+    "18001": "Adams County",
+    "18003": "Allen County",
+    "18005": "Bartholomew County",
+    "18007": "Benton County",
+    "18009": "Blackford County",
+    "18011": "Boone County",
+    "18013": "Brown County",
+    "18015": "Carroll County",
+    "18017": "Cass County",
+    "18019": "Clark County",
+    "18021": "Clay County",
+    "18023": "Clinton County",
+    "18025": "Crawford County",
+    "18027": "Daviess County",
+    "18029": "Dearborn County",
+    "18031": "Decatur County",
+    "18033": "DeKalb County",
+    "18035": "Delaware County",
+    "18037": "Dubois County",
+    "18039": "Elkhart County",
+    "18041": "Fayette County",
+    "18043": "Floyd County",
+    "18045": "Fountain County",
+    "18047": "Franklin County",
+    "18049": "Fulton County",
+    "18051": "Gibson County",
+    "18053": "Grant County",
+    "18055": "Greene County",
+    "18057": "Hamilton County",
+    "18059": "Hancock County",
+    "18061": "Harrison County",
+    "18063": "Hendricks County",
+    "18065": "Henry County",
+    "18067": "Howard County",
+    "18069": "Huntington County",
+    "18071": "Jackson County",
+    "18073": "Jasper County",
+    "18075": "Jay County",
+    "18077": "Jefferson County",
+    "18079": "Jennings County",
+    "18081": "Johnson County",
+    "18083": "Knox County",
+    "18085": "Kosciusko County",
+    "18087": "LaGrange County",
+    "18089": "Lake County",
+    "18091": "LaPorte County",
+    "18093": "Lawrence County",
+    "18095": "Madison County",
+    "18097": "Marion County",
+    "18099": "Marshall County",
+    "18101": "Martin County",
+    "18103": "Miami County",
+    "18105": "Monroe County",
+    "18107": "Montgomery County",
+    "18109": "Morgan County",
+    "18111": "Newton County",
+    "18113": "Noble County",
+    "18115": "Ohio County",
+    "18117": "Orange County",
+    "18119": "Owen County",
+    "18121": "Parke County",
+    "18123": "Perry County",
+    "18125": "Pike County",
+    "18127": "Porter County",
+    "18129": "Posey County",
+    "18131": "Pulaski County",
+    "18133": "Putnam County",
+    "18135": "Randolph County",
+    "18137": "Ripley County",
+    "18139": "Rush County",
+    "18141": "St. Joseph County",
+    "18143": "Scott County",
+    "18145": "Shelby County",
+    "18147": "Spencer County",
+    "18149": "Starke County",
+    "18151": "Steuben County",
+    "18153": "Sullivan County",
+    "18155": "Switzerland County",
+    "18157": "Tippecanoe County",
+    "18159": "Tipton County",
+    "18161": "Union County",
+    "18163": "Vanderburgh County",
+    "18165": "Vermillion County",
+    "18167": "Vigo County",
+    "18169": "Wabash County",
+    "18171": "Warren County",
+    "18173": "Warrick County",
+    "18175": "Washington County",
+    "18177": "Wayne County",
+    "18179": "Wells County",
+    "18181": "White County",
+    "18183": "Whitley County",
+    "19001": "Adair County",
+    "19003": "Adams County",
+    "19005": "Allamakee County",
+    "19007": "Appanoose County",
+    "19009": "Audubon County",
+    "19011": "Benton County",
+    "19013": "Black Hawk County",
+    "19015": "Boone County",
+    "19017": "Bremer County",
+    "19019": "Buchanan County",
+    "19021": "Buena Vista County",
+    "19023": "Butler County",
+    "19025": "Calhoun County",
+    "19027": "Carroll County",
+    "19029": "Cass County",
+    "19031": "Cedar County",
+    "19033": "Cerro Gordo County",
+    "19035": "Cherokee County",
+    "19037": "Chickasaw County",
+    "19039": "Clarke County",
+    "19041": "Clay County",
+    "19043": "Clayton County",
+    "19045": "Clinton County",
+    "19047": "Crawford County",
+    "19049": "Dallas County",
+    "19051": "Davis County",
+    "19053": "Decatur County",
+    "19055": "Delaware County",
+    "19057": "Des Moines County",
+    "19059": "Dickinson County",
+    "19061": "Dubuque County",
+    "19063": "Emmet County",
+    "19065": "Fayette County",
+    "19067": "Floyd County",
+    "19069": "Franklin County",
+    "19071": "Fremont County",
+    "19073": "Greene County",
+    "19075": "Grundy County",
+    "19077": "Guthrie County",
+    "19079": "Hamilton County",
+    "19081": "Hancock County",
+    "19083": "Hardin County",
+    "19085": "Harrison County",
+    "19087": "Henry County",
+    "19089": "Howard County",
+    "19091": "Humboldt County",
+    "19093": "Ida County",
+    "19095": "Iowa County",
+    "19097": "Jackson County",
+    "19099": "Jasper County",
+    "19101": "Jefferson County",
+    "19103": "Johnson County",
+    "19105": "Jones County",
+    "19107": "Keokuk County",
+    "19109": "Kossuth County",
+    "19111": "Lee County",
+    "19113": "Linn County",
+    "19115": "Louisa County",
+    "19117": "Lucas County",
+    "19119": "Lyon County",
+    "19121": "Madison County",
+    "19123": "Mahaska County",
+    "19125": "Marion County",
+    "19127": "Marshall County",
+    "19129": "Mills County",
+    "19131": "Mitchell County",
+    "19133": "Monona County",
+    "19135": "Monroe County",
+    "19137": "Montgomery County",
+    "19139": "Muscatine County",
+    "19141": "O'Brien County",
+    "19143": "Osceola County",
+    "19145": "Page County",
+    "19147": "Palo Alto County",
+    "19149": "Plymouth County",
+    "19151": "Pocahontas County",
+    "19153": "Polk County",
+    "19155": "Pottawattamie County",
+    "19157": "Poweshiek County",
+    "19159": "Ringgold County",
+    "19161": "Sac County",
+    "19163": "Scott County",
+    "19165": "Shelby County",
+    "19167": "Sioux County",
+    "19169": "Story County",
+    "19171": "Tama County",
+    "19173": "Taylor County",
+    "19175": "Union County",
+    "19177": "Van Buren County",
+    "19179": "Wapello County",
+    "19181": "Warren County",
+    "19183": "Washington County",
+    "19185": "Wayne County",
+    "19187": "Webster County",
+    "19189": "Winnebago County",
+    "19191": "Winneshiek County",
+    "19193": "Woodbury County",
+    "19195": "Worth County",
+    "19197": "Wright County",
+    "20001": "Allen County",
+    "20003": "Anderson County",
+    "20005": "Atchison County",
+    "20007": "Barber County",
+    "20009": "Barton County",
+    "20011": "Bourbon County",
+    "20013": "Brown County",
+    "20015": "Butler County",
+    "20017": "Chase County",
+    "20019": "Chautauqua County",
+    "20021": "Cherokee County",
+    "20023": "Cheyenne County",
+    "20025": "Clark County",
+    "20027": "Clay County",
+    "20029": "Cloud County",
+    "20031": "Coffey County",
+    "20033": "Comanche County",
+    "20035": "Cowley County",
+    "20037": "Crawford County",
+    "20039": "Decatur County",
+    "20041": "Dickinson County",
+    "20043": "Doniphan County",
+    "20045": "Douglas County",
+    "20047": "Edwards County",
+    "20049": "Elk County",
+    "20051": "Ellis County",
+    "20053": "Ellsworth County",
+    "20055": "Finney County",
+    "20057": "Ford County",
+    "20059": "Franklin County",
+    "20061": "Geary County",
+    "20063": "Gove County",
+    "20065": "Graham County",
+    "20067": "Grant County",
+    "20069": "Gray County",
+    "20071": "Greeley County",
+    "20073": "Greenwood County",
+    "20075": "Hamilton County",
+    "20077": "Harper County",
+    "20079": "Harvey County",
+    "20081": "Haskell County",
+    "20083": "Hodgeman County",
+    "20085": "Jackson County",
+    "20087": "Jefferson County",
+    "20089": "Jewell County",
+    "20091": "Johnson County",
+    "20093": "Kearny County",
+    "20095": "Kingman County",
+    "20097": "Kiowa County",
+    "20099": "Labette County",
+    "20101": "Lane County",
+    "20103": "Leavenworth County",
+    "20105": "Lincoln County",
+    "20107": "Linn County",
+    "20109": "Logan County",
+    "20111": "Lyon County",
+    "20113": "McPherson County",
+    "20115": "Marion County",
+    "20117": "Marshall County",
+    "20119": "Meade County",
+    "20121": "Miami County",
+    "20123": "Mitchell County",
+    "20125": "Montgomery County",
+    "20127": "Morris County",
+    "20129": "Morton County",
+    "20131": "Nemaha County",
+    "20133": "Neosho County",
+    "20135": "Ness County",
+    "20137": "Norton County",
+    "20139": "Osage County",
+    "20141": "Osborne County",
+    "20143": "Ottawa County",
+    "20145": "Pawnee County",
+    "20147": "Phillips County",
+    "20149": "Pottawatomie County",
+    "20151": "Pratt County",
+    "20153": "Rawlins County",
+    "20155": "Reno County",
+    "20157": "Republic County",
+    "20159": "Rice County",
+    "20161": "Riley County",
+    "20163": "Rooks County",
+    "20165": "Rush County",
+    "20167": "Russell County",
+    "20169": "Saline County",
+    "20171": "Scott County",
+    "20173": "Sedgwick County",
+    "20175": "Seward County",
+    "20177": "Shawnee County",
+    "20179": "Sheridan County",
+    "20181": "Sherman County",
+    "20183": "Smith County",
+    "20185": "Stafford County",
+    "20187": "Stanton County",
+    "20189": "Stevens County",
+    "20191": "Sumner County",
+    "20193": "Thomas County",
+    "20195": "Trego County",
+    "20197": "Wabaunsee County",
+    "20199": "Wallace County",
+    "20201": "Washington County",
+    "20203": "Wichita County",
+    "20205": "Wilson County",
+    "20207": "Woodson County",
+    "20209": "Wyandotte County",
+    "21001": "Adair County",
+    "21003": "Allen County",
+    "21005": "Anderson County",
+    "21007": "Ballard County",
+    "21009": "Barren County",
+    "21011": "Bath County",
+    "21013": "Bell County",
+    "21015": "Boone County",
+    "21017": "Bourbon County",
+    "21019": "Boyd County",
+    "21021": "Boyle County",
+    "21023": "Bracken County",
+    "21025": "Breathitt County",
+    "21027": "Breckinridge County",
+    "21029": "Bullitt County",
+    "21031": "Butler County",
+    "21033": "Caldwell County",
+    "21035": "Calloway County",
+    "21037": "Campbell County",
+    "21039": "Carlisle County",
+    "21041": "Carroll County",
+    "21043": "Carter County",
+    "21045": "Casey County",
+    "21047": "Christian County",
+    "21049": "Clark County",
+    "21051": "Clay County",
+    "21053": "Clinton County",
+    "21055": "Crittenden County",
+    "21057": "Cumberland County",
+    "21059": "Daviess County",
+    "21061": "Edmonson County",
+    "21063": "Elliott County",
+    "21065": "Estill County",
+    "21067": "Fayette County",
+    "21069": "Fleming County",
+    "21071": "Floyd County",
+    "21073": "Franklin County",
+    "21075": "Fulton County",
+    "21077": "Gallatin County",
+    "21079": "Garrard County",
+    "21081": "Grant County",
+    "21083": "Graves County",
+    "21085": "Grayson County",
+    "21087": "Green County",
+    "21089": "Greenup County",
+    "21091": "Hancock County",
+    "21093": "Hardin County",
+    "21095": "Harlan County",
+    "21097": "Harrison County",
+    "21099": "Hart County",
+    "21101": "Henderson County",
+    "21103": "Henry County",
+    "21105": "Hickman County",
+    "21107": "Hopkins County",
+    "21109": "Jackson County",
+    "21111": "Jefferson County",
+    "21113": "Jessamine County",
+    "21115": "Johnson County",
+    "21117": "Kenton County",
+    "21119": "Knott County",
+    "21121": "Knox County",
+    "21123": "Larue County",
+    "21125": "Laurel County",
+    "21127": "Lawrence County",
+    "21129": "Lee County",
+    "21131": "Leslie County",
+    "21133": "Letcher County",
+    "21135": "Lewis County",
+    "21137": "Lincoln County",
+    "21139": "Livingston County",
+    "21141": "Logan County",
+    "21143": "Lyon County",
+    "21145": "McCracken County",
+    "21147": "McCreary County",
+    "21149": "McLean County",
+    "21151": "Madison County",
+    "21153": "Magoffin County",
+    "21155": "Marion County",
+    "21157": "Marshall County",
+    "21159": "Martin County",
+    "21161": "Mason County",
+    "21163": "Meade County",
+    "21165": "Menifee County",
+    "21167": "Mercer County",
+    "21169": "Metcalfe County",
+    "21171": "Monroe County",
+    "21173": "Montgomery County",
+    "21175": "Morgan County",
+    "21177": "Muhlenberg County",
+    "21179": "Nelson County",
+    "21181": "Nicholas County",
+    "21183": "Ohio County",
+    "21185": "Oldham County",
+    "21187": "Owen County",
+    "21189": "Owsley County",
+    "21191": "Pendleton County",
+    "21193": "Perry County",
+    "21195": "Pike County",
+    "21197": "Powell County",
+    "21199": "Pulaski County",
+    "21201": "Robertson County",
+    "21203": "Rockcastle County",
+    "21205": "Rowan County",
+    "21207": "Russell County",
+    "21209": "Scott County",
+    "21211": "Shelby County",
+    "21213": "Simpson County",
+    "21215": "Spencer County",
+    "21217": "Taylor County",
+    "21219": "Todd County",
+    "21221": "Trigg County",
+    "21223": "Trimble County",
+    "21225": "Union County",
+    "21227": "Warren County",
+    "21229": "Washington County",
+    "21231": "Wayne County",
+    "21233": "Webster County",
+    "21235": "Whitley County",
+    "21237": "Wolfe County",
+    "21239": "Woodford County",
+    "22001": "Acadia Parish",
+    "22003": "Allen Parish",
+    "22005": "Ascension Parish",
+    "22007": "Assumption Parish",
+    "22009": "Avoyelles Parish",
+    "22011": "Beauregard Parish",
+    "22013": "Bienville Parish",
+    "22015": "Bossier Parish",
+    "22017": "Caddo Parish",
+    "22019": "Calcasieu Parish",
+    "22021": "Caldwell Parish",
+    "22023": "Cameron Parish",
+    "22025": "Catahoula Parish",
+    "22027": "Claiborne Parish",
+    "22029": "Concordia Parish",
+    "22031": "De Soto Parish",
+    "22033": "East Baton Rouge Parish",
+    "22035": "East Carroll Parish",
+    "22037": "East Feliciana Parish",
+    "22039": "Evangeline Parish",
+    "22041": "Franklin Parish",
+    "22043": "Grant Parish",
+    "22045": "Iberia Parish",
+    "22047": "Iberville Parish",
+    "22049": "Jackson Parish",
+    "22051": "Jefferson Parish",
+    "22053": "Jefferson Davis Parish",
+    "22055": "Lafayette Parish",
+    "22057": "Lafourche Parish",
+    "22059": "LaSalle Parish",
+    "22061": "Lincoln Parish",
+    "22063": "Livingston Parish",
+    "22065": "Madison Parish",
+    "22067": "Morehouse Parish",
+    "22069": "Natchitoches Parish",
+    "22071": "Orleans Parish",
+    "22073": "Ouachita Parish",
+    "22075": "Plaquemines Parish",
+    "22077": "Pointe Coupee Parish",
+    "22079": "Rapides Parish",
+    "22081": "Red River Parish",
+    "22083": "Richland Parish",
+    "22085": "Sabine Parish",
+    "22087": "St. Bernard Parish",
+    "22089": "St. Charles Parish",
+    "22091": "St. Helena Parish",
+    "22093": "St. James Parish",
+    "22095": "St. John the Baptist Parish",
+    "22097": "St. Landry Parish",
+    "22099": "St. Martin Parish",
+    "22101": "St. Mary Parish",
+    "22103": "St. Tammany Parish",
+    "22105": "Tangipahoa Parish",
+    "22107": "Tensas Parish",
+    "22109": "Terrebonne Parish",
+    "22111": "Union Parish",
+    "22113": "Vermilion Parish",
+    "22115": "Vernon Parish",
+    "22117": "Washington Parish",
+    "22119": "Webster Parish",
+    "22121": "West Baton Rouge Parish",
+    "22123": "West Carroll Parish",
+    "22125": "West Feliciana Parish",
+    "22127": "Winn Parish",
+    "23001": "Androscoggin County",
+    "23003": "Aroostook County",
+    "23005": "Cumberland County",
+    "23007": "Franklin County",
+    "23009": "Hancock County",
+    "23011": "Kennebec County",
+    "23013": "Knox County",
+    "23015": "Lincoln County",
+    "23017": "Oxford County",
+    "23019": "Penobscot County",
+    "23021": "Piscataquis County",
+    "23023": "Sagadahoc County",
+    "23025": "Somerset County",
+    "23027": "Waldo County",
+    "23029": "Washington County",
+    "23031": "York County",
+    "24001": "Allegany County",
+    "24003": "Anne Arundel County",
+    "24005": "Baltimore County",
+    "24009": "Calvert County",
+    "24011": "Caroline County",
+    "24013": "Carroll County",
+    "24015": "Cecil County",
+    "24017": "Charles County",
+    "24019": "Dorchester County",
+    "24021": "Frederick County",
+    "24023": "Garrett County",
+    "24025": "Harford County",
+    "24027": "Howard County",
+    "24029": "Kent County",
+    "24031": "Montgomery County",
+    "24033": "Prince George's County",
+    "24035": "Queen Anne's County",
+    "24037": "St. Mary's County",
+    "24039": "Somerset County",
+    "24041": "Talbot County",
+    "24043": "Washington County",
+    "24045": "Wicomico County",
+    "24047": "Worcester County",
+    "24510": "Baltimore City",
+    "25001": "Barnstable County",
+    "25003": "Berkshire County",
+    "25005": "Bristol County",
+    "25007": "Dukes County",
+    "25009": "Essex County",
+    "25011": "Franklin County",
+    "25013": "Hampden County",
+    "25015": "Hampshire County",
+    "25017": "Middlesex County",
+    "25019": "Nantucket County",
+    "25021": "Norfolk County",
+    "25023": "Plymouth County",
+    "25025": "Suffolk County",
+    "25027": "Worcester County",
+    "26001": "Alcona County",
+    "26003": "Alger County",
+    "26005": "Allegan County",
+    "26007": "Alpena County",
+    "26009": "Antrim County",
+    "26011": "Arenac County",
+    "26013": "Baraga County",
+    "26015": "Barry County",
+    "26017": "Bay County",
+    "26019": "Benzie County",
+    "26021": "Berrien County",
+    "26023": "Branch County",
+    "26025": "Calhoun County",
+    "26027": "Cass County",
+    "26029": "Charlevoix County",
+    "26031": "Cheboygan County",
+    "26033": "Chippewa County",
+    "26035": "Clare County",
+    "26037": "Clinton County",
+    "26039": "Crawford County",
+    "26041": "Delta County",
+    "26043": "Dickinson County",
+    "26045": "Eaton County",
+    "26047": "Emmet County",
+    "26049": "Genesee County",
+    "26051": "Gladwin County",
+    "26053": "Gogebic County",
+    "26055": "Grand Traverse County",
+    "26057": "Gratiot County",
+    "26059": "Hillsdale County",
+    "26061": "Houghton County",
+    "26063": "Huron County",
+    "26065": "Ingham County",
+    "26067": "Ionia County",
+    "26069": "Iosco County",
+    "26071": "Iron County",
+    "26073": "Isabella County",
+    "26075": "Jackson County",
+    "26077": "Kalamazoo County",
+    "26079": "Kalkaska County",
+    "26081": "Kent County",
+    "26083": "Keweenaw County",
+    "26085": "Lake County",
+    "26087": "Lapeer County",
+    "26089": "Leelanau County",
+    "26091": "Lenawee County",
+    "26093": "Livingston County",
+    "26095": "Luce County",
+    "26097": "Mackinac County",
+    "26099": "Macomb County",
+    "26101": "Manistee County",
+    "26103": "Marquette County",
+    "26105": "Mason County",
+    "26107": "Mecosta County",
+    "26109": "Menominee County",
+    "26111": "Midland County",
+    "26113": "Missaukee County",
+    "26115": "Monroe County",
+    "26117": "Montcalm County",
+    "26119": "Montmorency County",
+    "26121": "Muskegon County",
+    "26123": "Newaygo County",
+    "26125": "Oakland County",
+    "26127": "Oceana County",
+    "26129": "Ogemaw County",
+    "26131": "Ontonagon County",
+    "26133": "Osceola County",
+    "26135": "Oscoda County",
+    "26137": "Otsego County",
+    "26139": "Ottawa County",
+    "26141": "Presque Isle County",
+    "26143": "Roscommon County",
+    "26145": "Saginaw County",
+    "26147": "St. Clair County",
+    "26149": "St. Joseph County",
+    "26151": "Sanilac County",
+    "26153": "Schoolcraft County",
+    "26155": "Shiawassee County",
+    "26157": "Tuscola County",
+    "26159": "Van Buren County",
+    "26161": "Washtenaw County",
+    "26163": "Wayne County",
+    "26165": "Wexford County",
+    "27001": "Aitkin County",
+    "27003": "Anoka County",
+    "27005": "Becker County",
+    "27007": "Beltrami County",
+    "27009": "Benton County",
+    "27011": "Big Stone County",
+    "27013": "Blue Earth County",
+    "27015": "Brown County",
+    "27017": "Carlton County",
+    "27019": "Carver County",
+    "27021": "Cass County",
+    "27023": "Chippewa County",
+    "27025": "Chisago County",
+    "27027": "Clay County",
+    "27029": "Clearwater County",
+    "27031": "Cook County",
+    "27033": "Cottonwood County",
+    "27035": "Crow Wing County",
+    "27037": "Dakota County",
+    "27039": "Dodge County",
+    "27041": "Douglas County",
+    "27043": "Faribault County",
+    "27045": "Fillmore County",
+    "27047": "Freeborn County",
+    "27049": "Goodhue County",
+    "27051": "Grant County",
+    "27053": "Hennepin County",
+    "27055": "Houston County",
+    "27057": "Hubbard County",
+    "27059": "Isanti County",
+    "27061": "Itasca County",
+    "27063": "Jackson County",
+    "27065": "Kanabec County",
+    "27067": "Kandiyohi County",
+    "27069": "Kittson County",
+    "27071": "Koochiching County",
+    "27073": "Lac qui Parle County",
+    "27075": "Lake County",
+    "27077": "Lake of the Woods County",
+    "27079": "Le Sueur County",
+    "27081": "Lincoln County",
+    "27083": "Lyon County",
+    "27085": "McLeod County",
+    "27087": "Mahnomen County",
+    "27089": "Marshall County",
+    "27091": "Martin County",
+    "27093": "Meeker County",
+    "27095": "Mille Lacs County",
+    "27097": "Morrison County",
+    "27099": "Mower County",
+    "27101": "Murray County",
+    "27103": "Nicollet County",
+    "27105": "Nobles County",
+    "27107": "Norman County",
+    "27109": "Olmsted County",
+    "27111": "Otter Tail County",
+    "27113": "Pennington County",
+    "27115": "Pine County",
+    "27117": "Pipestone County",
+    "27119": "Polk County",
+    "27121": "Pope County",
+    "27123": "Ramsey County",
+    "27125": "Red Lake County",
+    "27127": "Redwood County",
+    "27129": "Renville County",
+    "27131": "Rice County",
+    "27133": "Rock County",
+    "27135": "Roseau County",
+    "27137": "St. Louis County",
+    "27139": "Scott County",
+    "27141": "Sherburne County",
+    "27143": "Sibley County",
+    "27145": "Stearns County",
+    "27147": "Steele County",
+    "27149": "Stevens County",
+    "27151": "Swift County",
+    "27153": "Todd County",
+    "27155": "Traverse County",
+    "27157": "Wabasha County",
+    "27159": "Wadena County",
+    "27161": "Waseca County",
+    "27163": "Washington County",
+    "27165": "Watonwan County",
+    "27167": "Wilkin County",
+    "27169": "Winona County",
+    "27171": "Wright County",
+    "27173": "Yellow Medicine County",
+    "28001": "Adams County",
+    "28003": "Alcorn County",
+    "28005": "Amite County",
+    "28007": "Attala County",
+    "28009": "Benton County",
+    "28011": "Bolivar County",
+    "28013": "Calhoun County",
+    "28015": "Carroll County",
+    "28017": "Chickasaw County",
+    "28019": "Choctaw County",
+    "28021": "Claiborne County",
+    "28023": "Clarke County",
+    "28025": "Clay County",
+    "28027": "Coahoma County",
+    "28029": "Copiah County",
+    "28031": "Covington County",
+    "28033": "DeSoto County",
+    "28035": "Forrest County",
+    "28037": "Franklin County",
+    "28039": "George County",
+    "28041": "Greene County",
+    "28043": "Grenada County",
+    "28045": "Hancock County",
+    "28047": "Harrison County",
+    "28049": "Hinds County",
+    "28051": "Holmes County",
+    "28053": "Humphreys County",
+    "28055": "Issaquena County",
+    "28057": "Itawamba County",
+    "28059": "Jackson County",
+    "28061": "Jasper County",
+    "28063": "Jefferson County",
+    "28065": "Jefferson Davis County",
+    "28067": "Jones County",
+    "28069": "Kemper County",
+    "28071": "Lafayette County",
+    "28073": "Lamar County",
+    "28075": "Lauderdale County",
+    "28077": "Lawrence County",
+    "28079": "Leake County",
+    "28081": "Lee County",
+    "28083": "Leflore County",
+    "28085": "Lincoln County",
+    "28087": "Lowndes County",
+    "28089": "Madison County",
+    "28091": "Marion County",
+    "28093": "Marshall County",
+    "28095": "Monroe County",
+    "28097": "Montgomery County",
+    "28099": "Neshoba County",
+    "28101": "Newton County",
+    "28103": "Noxubee County",
+    "28105": "Oktibbeha County",
+    "28107": "Panola County",
+    "28109": "Pearl River County",
+    "28111": "Perry County",
+    "28113": "Pike County",
+    "28115": "Pontotoc County",
+    "28117": "Prentiss County",
+    "28119": "Quitman County",
+    "28121": "Rankin County",
+    "28123": "Scott County",
+    "28125": "Sharkey County",
+    "28127": "Simpson County",
+    "28129": "Smith County",
+    "28131": "Stone County",
+    "28133": "Sunflower County",
+    "28135": "Tallahatchie County",
+    "28137": "Tate County",
+    "28139": "Tippah County",
+    "28141": "Tishomingo County",
+    "28143": "Tunica County",
+    "28145": "Union County",
+    "28147": "Walthall County",
+    "28149": "Warren County",
+    "28151": "Washington County",
+    "28153": "Wayne County",
+    "28155": "Webster County",
+    "28157": "Wilkinson County",
+    "28159": "Winston County",
+    "28161": "Yalobusha County",
+    "28163": "Yazoo County",
+    "29001": "Adair County",
+    "29003": "Andrew County",
+    "29005": "Atchison County",
+    "29007": "Audrain County",
+    "29009": "Barry County",
+    "29011": "Barton County",
+    "29013": "Bates County",
+    "29015": "Benton County",
+    "29017": "Bollinger County",
+    "29019": "Boone County",
+    "29021": "Buchanan County",
+    "29023": "Butler County",
+    "29025": "Caldwell County",
+    "29027": "Callaway County",
+    "29029": "Camden County",
+    "29031": "Cape Girardeau County",
+    "29033": "Carroll County",
+    "29035": "Carter County",
+    "29037": "Cass County",
+    "29039": "Cedar County",
+    "29041": "Chariton County",
+    "29043": "Christian County",
+    "29045": "Clark County",
+    "29047": "Clay County",
+    "29049": "Clinton County",
+    "29051": "Cole County",
+    "29053": "Cooper County",
+    "29055": "Crawford County",
+    "29057": "Dade County",
+    "29059": "Dallas County",
+    "29061": "Daviess County",
+    "29063": "DeKalb County",
+    "29065": "Dent County",
+    "29067": "Douglas County",
+    "29069": "Dunklin County",
+    "29071": "Franklin County",
+    "29073": "Gasconade County",
+    "29075": "Gentry  County",
+    "29077": "Greene County",
+    "29079": "Grundy County",
+    "29081": "Harrison County",
+    "29083": "Henry County",
+    "29085": "Hickory County",
+    "29087": "Holt County",
+    "29089": "Howard County",
+    "29091": "Howell County",
+    "29093": "Iron County",
+    "29095": "Jackson County",
+    "29097": "Jasper County",
+    "29099": "Jefferson County",
+    "29101": "Johnson County",
+    "29103": "Knox County",
+    "29105": "Laclede County",
+    "29107": "Lafayette County",
+    "29109": "Lawrence County",
+    "29111": "Lewis County",
+    "29113": "Lincoln County",
+    "29115": "Linn County",
+    "29117": "Livingston County",
+    "29119": "McDonald County",
+    "29121": "Macon County",
+    "29123": "Madison County",
+    "29125": "Maries County",
+    "29127": "Marion County",
+    "29129": "Mercer County",
+    "29131": "Miller County",
+    "29133": "Mississippi County",
+    "29135": "Moniteau County",
+    "29137": "Monroe County",
+    "29139": "Montgomery County",
+    "29141": "Morgan County",
+    "29143": "New Madrid County",
+    "29145": "Newton County",
+    "29147": "Nodaway County",
+    "29149": "Oregon County",
+    "29151": "Osage County",
+    "29153": "Ozark County",
+    "29155": "Pemiscot County",
+    "29157": "Perry County",
+    "29159": "Pettis County",
+    "29161": "Phelps County",
+    "29163": "Pike County",
+    "29165": "Platte County",
+    "29167": "Polk County",
+    "29169": "Pulaski County",
+    "29171": "Putnam County",
+    "29173": "Ralls County",
+    "29175": "Randolph County",
+    "29177": "Ray County",
+    "29179": "Reynolds County",
+    "29181": "Ripley County",
+    "29183": "St. Charles County",
+    "29185": "St. Clair County",
+    "29186": "Ste. Genevieve County",
+    "29187": "St. Francois County",
+    "29189": "St. Louis County",
+    "29195": "Saline County",
+    "29197": "Schuyler County",
+    "29199": "Scotland County",
+    "29201": "Scott County",
+    "29203": "Shannon County",
+    "29205": "Shelby County",
+    "29207": "Stoddard County",
+    "29209": "Stone County",
+    "29211": "Sullivan County",
+    "29213": "Taney County",
+    "29215": "Texas County",
+    "29217": "Vernon County",
+    "29219": "Warren County",
+    "29221": "Washington County",
+    "29223": "Wayne County",
+    "29225": "Webster County",
+    "29227": "Worth County",
+    "29229": "Wright County",
+    "29510": "St. Louis City",
+    "30001": "Beaverhead County",
+    "30003": "Big Horn County",
+    "30005": "Blaine County",
+    "30007": "Broadwater County",
+    "30009": "Carbon County",
+    "30011": "Carter County",
+    "30013": "Cascade County",
+    "30015": "Chouteau County",
+    "30017": "Custer County",
+    "30019": "Daniels County",
+    "30021": "Dawson County",
+    "30023": "Deer Lodge County",
+    "30025": "Fallon County",
+    "30027": "Fergus County",
+    "30029": "Flathead County",
+    "30031": "Gallatin County",
+    "30033": "Garfield County",
+    "30035": "Glacier County",
+    "30037": "Golden Valley County",
+    "30039": "Granite County",
+    "30041": "Hill County",
+    "30043": "Jefferson County",
+    "30045": "Judith Basin County",
+    "30047": "Lake County",
+    "30049": "Lewis and Clark County",
+    "30051": "Liberty County",
+    "30053": "Lincoln County",
+    "30055": "McCone County",
+    "30057": "Madison County",
+    "30059": "Meagher County",
+    "30061": "Mineral County",
+    "30063": "Missoula County",
+    "30065": "Musselshell County",
+    "30067": "Park County",
+    "30069": "Petroleum County",
+    "30071": "Phillips County",
+    "30073": "Pondera County",
+    "30075": "Powder River County",
+    "30077": "Powell County",
+    "30079": "Prairie County",
+    "30081": "Ravalli County",
+    "30083": "Richland County",
+    "30085": "Roosevelt County",
+    "30087": "Rosebud County",
+    "30089": "Sanders County",
+    "30091": "Sheridan County",
+    "30093": "Silver Bow County",
+    "30095": "Stillwater County",
+    "30097": "Sweet Grass County",
+    "30099": "Teton County",
+    "30101": "Toole County",
+    "30103": "Treasure County",
+    "30105": "Valley County",
+    "30107": "Wheatland County",
+    "30109": "Wibaux County",
+    "30111": "Yellowstone County",
+    "30113": "Yellowstone National Park - Part",
+    "31001": "Adams County",
+    "31003": "Antelope County",
+    "31005": "Arthur County",
+    "31007": "Banner County",
+    "31009": "Blaine County",
+    "31011": "Boone County",
+    "31013": "Box Butte County",
+    "31015": "Boyd County",
+    "31017": "Brown County",
+    "31019": "Buffalo County",
+    "31021": "Burt County",
+    "31023": "Butler County",
+    "31025": "Cass County",
+    "31027": "Cedar County",
+    "31029": "Chase County",
+    "31031": "Cherry County",
+    "31033": "Cheyenne County",
+    "31035": "Clay County",
+    "31037": "Colfax County",
+    "31039": "Cuming County",
+    "31041": "Custer County",
+    "31043": "Dakota County",
+    "31045": "Dawes County",
+    "31047": "Dawson County",
+    "31049": "Deuel County",
+    "31051": "Dixon County",
+    "31053": "Dodge County",
+    "31055": "Douglas County",
+    "31057": "Dundy County",
+    "31059": "Fillmore County",
+    "31061": "Franklin County",
+    "31063": "Frontier County",
+    "31065": "Furnas County",
+    "31067": "Gage County",
+    "31069": "Garden County",
+    "31071": "Garfield County",
+    "31073": "Gosper County",
+    "31075": "Grant County",
+    "31077": "Greeley County",
+    "31079": "Hall County",
+    "31081": "Hamilton County",
+    "31083": "Harlan County",
+    "31085": "Hayes County",
+    "31087": "Hitchcock County",
+    "31089": "Holt County",
+    "31091": "Hooker County",
+    "31093": "Howard County",
+    "31095": "Jefferson County",
+    "31097": "Johnson County",
+    "31099": "Kearney County",
+    "31101": "Keith County",
+    "31103": "Keya Paha County",
+    "31105": "Kimball County",
+    "31107": "Knox County",
+    "31109": "Lancaster County",
+    "31111": "Lincoln County",
+    "31113": "Logan County",
+    "31115": "Loup County",
+    "31117": "McPherson County",
+    "31119": "Madison County",
+    "31121": "Merrick County",
+    "31123": "Morrill County",
+    "31125": "Nance County",
+    "31127": "Nemaha County",
+    "31129": "Nuckolls County",
+    "31131": "Otoe County",
+    "31133": "Pawnee County",
+    "31135": "Perkins County",
+    "31137": "Phelps County",
+    "31139": "Pierce County",
+    "31141": "Platte County",
+    "31143": "Polk County",
+    "31145": "Red Willow County",
+    "31147": "Richardson County",
+    "31149": "Rock County",
+    "31151": "Saline County",
+    "31153": "Sarpy County",
+    "31155": "Saunders County",
+    "31157": "Scotts Bluff County",
+    "31159": "Seward County",
+    "31161": "Sheridan County",
+    "31163": "Sherman County",
+    "31165": "Sioux County",
+    "31167": "Stanton County",
+    "31169": "Thayer County",
+    "31171": "Thomas County",
+    "31173": "Thurston County",
+    "31175": "Valley County",
+    "31177": "Washington County",
+    "31179": "Wayne County",
+    "31181": "Webster County",
+    "31183": "Wheeler County",
+    "31185": "York County",
+    "32001": "Churchill County",
+    "32003": "Clark County",
+    "32005": "Douglas County",
+    "32007": "Elko County",
+    "32009": "Esmeralda County",
+    "32011": "Eureka County",
+    "32013": "Humboldt County",
+    "32015": "Lander County",
+    "32017": "Lincoln County",
+    "32019": "Lyon County",
+    "32021": "Mineral County",
+    "32023": "Nye County",
+    "32027": "Pershing County",
+    "32029": "Storey County",
+    "32031": "Washoe County",
+    "32033": "White Pine County",
+    "32510": "Carson City",
+    "33001": "Belknap County",
+    "33003": "Carroll County",
+    "33005": "Cheshire County",
+    "33007": "Coos County",
+    "33009": "Grafton County",
+    "33011": "Hillsborough County",
+    "33013": "Merrimack County",
+    "33015": "Rockingham County",
+    "33017": "Strafford County",
+    "33019": "Sullivan County",
+    "34001": "Atlantic County",
+    "34003": "Bergen County",
+    "34005": "Burlington County",
+    "34007": "Camden County",
+    "34009": "Cape May County",
+    "34011": "Cumberland County",
+    "34013": "Essex County",
+    "34015": "Gloucester County",
+    "34017": "Hudson County",
+    "34019": "Hunterdon County",
+    "34021": "Mercer County",
+    "34023": "Middlesex County",
+    "34025": "Monmouth County",
+    "34027": "Morris County",
+    "34029": "Ocean County",
+    "34031": "Passaic County",
+    "34033": "Salem County",
+    "34035": "Somerset County",
+    "34037": "Sussex County",
+    "34039": "Union County",
+    "34041": "Warren County",
+    "35001": "Bernalillo County",
+    "35003": "Catron County",
+    "35005": "Chaves County",
+    "35006": "Cibola County",
+    "35007": "Colfax County",
+    "35009": "Curry County",
+    "35011": "De Baca County",
+    "35013": "Dona Ana County",
+    "35015": "Eddy County",
+    "35017": "Grant County",
+    "35019": "Guadalupe County",
+    "35021": "Harding County",
+    "35023": "Hidalgo County",
+    "35025": "Lea County",
+    "35027": "Lincoln County",
+    "35028": "Los Alamos County",
+    "35029": "Luna County",
+    "35031": "McKinley County",
+    "35033": "Mora County",
+    "35035": "Otero County",
+    "35037": "Quay County",
+    "35039": "Rio Arriba County",
+    "35041": "Roosevelt County",
+    "35043": "Sandoval County",
+    "35045": "San Juan County",
+    "35047": "San Miguel County",
+    "35049": "Santa Fe County",
+    "35051": "Sierra County",
+    "35053": "Socorro County",
+    "35055": "Taos County",
+    "35057": "Torrance County",
+    "35059": "Union County",
+    "35061": "Valencia County",
+    "36001": "Albany County",
+    "36003": "Allegany County",
+    "36005": "Bronx County",
+    "36007": "Broome County",
+    "36009": "Cattaraugus County",
+    "36011": "Cayuga County",
+    "36013": "Chautauqua County",
+    "36015": "Chemung County",
+    "36017": "Chenango County",
+    "36019": "Clinton County",
+    "36021": "Columbia County",
+    "36023": "Cortland County",
+    "36025": "Delaware County",
+    "36027": "Dutchess County",
+    "36029": "Erie County",
+    "36031": "Essex County",
+    "36033": "Franklin County",
+    "36035": "Fulton County",
+    "36037": "Genesee County",
+    "36039": "Greene County",
+    "36041": "Hamilton County",
+    "36043": "Herkimer County",
+    "36045": "Jefferson County",
+    "36047": "Kings County",
+    "36049": "Lewis County",
+    "36051": "Livingston County",
+    "36053": "Madison County",
+    "36055": "Monroe County",
+    "36057": "Montgomery County",
+    "36059": "Nassau County",
+    "36061": "New York County",
+    "36063": "Niagara County",
+    "36065": "Oneida County",
+    "36067": "Onondaga County",
+    "36069": "Ontario County",
+    "36071": "Orange County",
+    "36073": "Orleans County",
+    "36075": "Oswego County",
+    "36077": "Otsego County",
+    "36079": "Putnam County",
+    "36081": "Queens County",
+    "36083": "Rensselaer County",
+    "36085": "Richmond County",
+    "36087": "Rockland County",
+    "36089": "St. Lawrence County",
+    "36091": "Saratoga County",
+    "36093": "Schenectady County",
+    "36095": "Schoharie County",
+    "36097": "Schuyler County",
+    "36099": "Seneca County",
+    "36101": "Steuben County",
+    "36103": "Suffolk County",
+    "36105": "Sullivan County",
+    "36107": "Tioga County",
+    "36109": "Tompkins County",
+    "36111": "Ulster County",
+    "36113": "Warren County",
+    "36115": "Washington County",
+    "36117": "Wayne County",
+    "36119": "Westchester County",
+    "36121": "Wyoming County",
+    "36123": "Yates County",
+    "37001": "Alamance County",
+    "37003": "Alexander County",
+    "37005": "Alleghany County",
+    "37007": "Anson County",
+    "37009": "Ashe County",
+    "37011": "Avery County",
+    "37013": "Beaufort County",
+    "37015": "Bertie County",
+    "37017": "Bladen County",
+    "37019": "Brunswick County",
+    "37021": "Buncombe County",
+    "37023": "Burke County",
+    "37025": "Cabarrus County",
+    "37027": "Caldwell County",
+    "37029": "Camden County",
+    "37031": "Carteret County",
+    "37033": "Caswell County",
+    "37035": "Catawba County",
+    "37037": "Chatham County",
+    "37039": "Cherokee County",
+    "37041": "Chowan County",
+    "37043": "Clay County",
+    "37045": "Cleveland County",
+    "37047": "Columbus County",
+    "37049": "Craven County",
+    "37051": "Cumberland County",
+    "37053": "Currituck County",
+    "37055": "Dare County",
+    "37057": "Davidson County",
+    "37059": "Davie County",
+    "37061": "Duplin County",
+    "37063": "Durham County",
+    "37065": "Edgecombe County",
+    "37067": "Forsyth County",
+    "37069": "Franklin County",
+    "37071": "Gaston County",
+    "37073": "Gates County",
+    "37075": "Graham County",
+    "37077": "Granville County",
+    "37079": "Greene County",
+    "37081": "Guilford County",
+    "37083": "Halifax County",
+    "37085": "Harnett County",
+    "37087": "Haywood County",
+    "37089": "Henderson County",
+    "37091": "Hertford County",
+    "37093": "Hoke County",
+    "37095": "Hyde County",
+    "37097": "Iredell County",
+    "37099": "Jackson County",
+    "37101": "Johnston County",
+    "37103": "Jones County",
+    "37105": "Lee County",
+    "37107": "Lenoir County",
+    "37109": "Lincoln County",
+    "37111": "McDowell County",
+    "37113": "Macon County",
+    "37115": "Madison County",
+    "37117": "Martin County",
+    "37119": "Mecklenburg County",
+    "37121": "Mitchell County",
+    "37123": "Montgomery County",
+    "37125": "Moore County",
+    "37127": "Nash County",
+    "37129": "New Hanover County",
+    "37131": "Northampton County",
+    "37133": "Onslow County",
+    "37135": "Orange County",
+    "37137": "Pamlico County",
+    "37139": "Pasquotank County",
+    "37141": "Pender County",
+    "37143": "Perquimans County",
+    "37145": "Person County",
+    "37147": "Pitt County",
+    "37149": "Polk County",
+    "37151": "Randolph County",
+    "37153": "Richmond County",
+    "37155": "Robeson County",
+    "37157": "Rockingham County",
+    "37159": "Rowan County",
+    "37161": "Rutherford County",
+    "37163": "Sampson County",
+    "37165": "Scotland County",
+    "37167": "Stanly County",
+    "37169": "Stokes County",
+    "37171": "Surry County",
+    "37173": "Swain County",
+    "37175": "Transylvania County",
+    "37177": "Tyrrell County",
+    "37179": "Union County",
+    "37181": "Vance County",
+    "37183": "Wake County",
+    "37185": "Warren County",
+    "37187": "Washington County",
+    "37189": "Watauga County",
+    "37191": "Wayne County",
+    "37193": "Wilkes County",
+    "37195": "Wilson County",
+    "37197": "Yadkin County",
+    "37199": "Yancey County",
+    "38001": "Adams County",
+    "38003": "Barnes County",
+    "38005": "Benson County",
+    "38007": "Billings County",
+    "38009": "Bottineau County",
+    "38011": "Bowman County",
+    "38013": "Burke County",
+    "38015": "Burleigh County",
+    "38017": "Cass County",
+    "38019": "Cavalier County",
+    "38021": "Dickey County",
+    "38023": "Divide County",
+    "38025": "Dunn County",
+    "38027": "Eddy County",
+    "38029": "Emmons County",
+    "38031": "Foster County",
+    "38033": "Golden Valley County",
+    "38035": "Grand Forks County",
+    "38037": "Grant County",
+    "38039": "Griggs County",
+    "38041": "Hettinger County",
+    "38043": "Kidder County",
+    "38045": "LaMoure County",
+    "38047": "Logan County",
+    "38049": "McHenry County",
+    "38051": "McIntosh County",
+    "38053": "McKenzie County",
+    "38055": "McLean County",
+    "38057": "Mercer County",
+    "38059": "Morton County",
+    "38061": "Mountrail County",
+    "38063": "Nelson County",
+    "38065": "Oliver County",
+    "38067": "Pembina County",
+    "38069": "Pierce County",
+    "38071": "Ramsey County",
+    "38073": "Ransom County",
+    "38075": "Renville County",
+    "38077": "Richland County",
+    "38079": "Rolette County",
+    "38081": "Sargent County",
+    "38083": "Sheridan County",
+    "38085": "Sioux County",
+    "38087": "Slope County",
+    "38089": "Stark County",
+    "38091": "Steele County",
+    "38093": "Stutsman County",
+    "38095": "Towner County",
+    "38097": "Traill County",
+    "38099": "Walsh County",
+    "38101": "Ward County",
+    "38103": "Wells County",
+    "38105": "Williams County",
+    "39001": "Adams County",
+    "39003": "Allen County",
+    "39005": "Ashland County",
+    "39007": "Ashtabula County",
+    "39009": "Athens County",
+    "39011": "Auglaize County",
+    "39013": "Belmont County",
+    "39015": "Brown County",
+    "39017": "Butler County",
+    "39019": "Carroll County",
+    "39021": "Champaign County",
+    "39023": "Clark County",
+    "39025": "Clermont County",
+    "39027": "Clinton County",
+    "39029": "Columbiana County",
+    "39031": "Coshocton County",
+    "39033": "Crawford County",
+    "39035": "Cuyahoga County",
+    "39037": "Darke County",
+    "39039": "Defiance County",
+    "39041": "Delaware County",
+    "39043": "Erie County",
+    "39045": "Fairfield County",
+    "39047": "Fayette County",
+    "39049": "Franklin County",
+    "39051": "Fulton County",
+    "39053": "Gallia County",
+    "39055": "Geauga County",
+    "39057": "Greene County",
+    "39059": "Guernsey County",
+    "39061": "Hamilton County",
+    "39063": "Hancock County",
+    "39065": "Hardin County",
+    "39067": "Harrison County",
+    "39069": "Henry County",
+    "39071": "Highland County",
+    "39073": "Hocking County",
+    "39075": "Holmes County",
+    "39077": "Huron County",
+    "39079": "Jackson County",
+    "39081": "Jefferson County",
+    "39083": "Knox County",
+    "39085": "Lake County",
+    "39087": "Lawrence County",
+    "39089": "Licking County",
+    "39091": "Logan County",
+    "39093": "Lorain County",
+    "39095": "Lucas County",
+    "39097": "Madison County",
+    "39099": "Mahoning County",
+    "39101": "Marion County",
+    "39103": "Medina County",
+    "39105": "Meigs County",
+    "39107": "Mercer County",
+    "39109": "Miami County",
+    "39111": "Monroe County",
+    "39113": "Montgomery County",
+    "39115": "Morgan County",
+    "39117": "Morrow County",
+    "39119": "Muskingum County",
+    "39121": "Noble County",
+    "39123": "Ottawa County",
+    "39125": "Paulding County",
+    "39127": "Perry County",
+    "39129": "Pickaway County",
+    "39131": "Pike County",
+    "39133": "Portage County",
+    "39135": "Preble County",
+    "39137": "Putnam County",
+    "39139": "Richland County",
+    "39141": "Ross County",
+    "39143": "Sandusky County",
+    "39145": "Scioto County",
+    "39147": "Seneca County",
+    "39149": "Shelby County",
+    "39151": "Stark County",
+    "39153": "Summit County",
+    "39155": "Trumbull County",
+    "39157": "Tuscarawas County",
+    "39159": "Union County",
+    "39161": "Van Wert County",
+    "39163": "Vinton County",
+    "39165": "Warren County",
+    "39167": "Washington County",
+    "39169": "Wayne County",
+    "39171": "Williams County",
+    "39173": "Wood County",
+    "39175": "Wyandot County",
+    "40001": "Adair County",
+    "40003": "Alfalfa County",
+    "40005": "Atoka County",
+    "40007": "Beaver County",
+    "40009": "Beckham County",
+    "40011": "Blaine County",
+    "40013": "Bryan County",
+    "40015": "Caddo County",
+    "40017": "Canadian County",
+    "40019": "Carter County",
+    "40021": "Cherokee County",
+    "40023": "Choctaw County",
+    "40025": "Cimarron County",
+    "40027": "Cleveland County",
+    "40029": "Coal County",
+    "40031": "Comanche County",
+    "40033": "Cotton County",
+    "40035": "Craig County",
+    "40037": "Creek County",
+    "40039": "Custer County",
+    "40041": "Delaware County",
+    "40043": "Dewey County",
+    "40045": "Ellis County",
+    "40047": "Garfield County",
+    "40049": "Garvin County",
+    "40051": "Grady County",
+    "40053": "Grant County",
+    "40055": "Greer County",
+    "40057": "Harmon County",
+    "40059": "Harper County",
+    "40061": "Haskell County",
+    "40063": "Hughes County",
+    "40065": "Jackson County",
+    "40067": "Jefferson County",
+    "40069": "Johnston County",
+    "40071": "Kay County",
+    "40073": "Kingfisher County",
+    "40075": "Kiowa County",
+    "40077": "Latimer County",
+    "40079": "Le Flore County",
+    "40081": "Lincoln County",
+    "40083": "Logan County",
+    "40085": "Love County",
+    "40087": "McClain County",
+    "40089": "McCurtain County",
+    "40091": "McIntosh County",
+    "40093": "Major County",
+    "40095": "Marshall County",
+    "40097": "Mayes County",
+    "40099": "Murray County",
+    "40101": "Muskogee County",
+    "40103": "Noble County",
+    "40105": "Nowata County",
+    "40107": "Okfuskee County",
+    "40109": "Oklahoma County",
+    "40111": "Okmulgee County",
+    "40113": "Osage County",
+    "40115": "Ottawa County",
+    "40117": "Pawnee County",
+    "40119": "Payne County",
+    "40121": "Pittsburg County",
+    "40123": "Pontotoc County",
+    "40125": "Pottawatomie County",
+    "40127": "Pushmataha County",
+    "40129": "Roger Mills County",
+    "40131": "Rogers County",
+    "40133": "Seminole County",
+    "40135": "Sequoyah County",
+    "40137": "Stephens County",
+    "40139": "Texas County",
+    "40141": "Tillman County",
+    "40143": "Tulsa County",
+    "40145": "Wagoner County",
+    "40147": "Washington County",
+    "40149": "Washita County",
+    "40151": "Woods County",
+    "40153": "Woodward County",
+    "41001": "Baker County",
+    "41003": "Benton County",
+    "41005": "Clackamas County",
+    "41007": "Clatsop County",
+    "41009": "Columbia County",
+    "41011": "Coos County",
+    "41013": "Crook County",
+    "41015": "Curry County",
+    "41017": "Deschutes County",
+    "41019": "Douglas County",
+    "41021": "Gilliam County",
+    "41023": "Grant County",
+    "41025": "Harney County",
+    "41027": "Hood River County",
+    "41029": "Jackson County",
+    "41031": "Jefferson County",
+    "41033": "Josephine County",
+    "41035": "Klamath County",
+    "41037": "Lake County",
+    "41039": "Lane County",
+    "41041": "Lincoln County",
+    "41043": "Linn County",
+    "41045": "Malheur County",
+    "41047": "Marion County",
+    "41049": "Morrow County",
+    "41051": "Multnomah County",
+    "41053": "Polk County",
+    "41055": "Sherman County",
+    "41057": "Tillamook County",
+    "41059": "Umatilla County",
+    "41061": "Union County",
+    "41063": "Wallowa County",
+    "41065": "Wasco County",
+    "41067": "Washington County",
+    "41069": "Wheeler County",
+    "41071": "Yamhill County",
+    "42001": "Adams County",
+    "42003": "Allegheny County",
+    "42005": "Armstrong County",
+    "42007": "Beaver County",
+    "42009": "Bedford County",
+    "42011": "Berks County",
+    "42013": "Blair County",
+    "42015": "Bradford County",
+    "42017": "Bucks County",
+    "42019": "Butler County",
+    "42021": "Cambria County",
+    "42023": "Cameron County",
+    "42025": "Carbon County",
+    "42027": "Centre County",
+    "42029": "Chester County",
+    "42031": "Clarion County",
+    "42033": "Clearfield County",
+    "42035": "Clinton County",
+    "42037": "Columbia County",
+    "42039": "Crawford County",
+    "42041": "Cumberland County",
+    "42043": "Dauphin County",
+    "42045": "Delaware County",
+    "42047": "Elk County",
+    "42049": "Erie County",
+    "42051": "Fayette County",
+    "42053": "Forest County",
+    "42055": "Franklin County",
+    "42057": "Fulton County",
+    "42059": "Greene County",
+    "42061": "Huntingdon County",
+    "42063": "Indiana County",
+    "42065": "Jefferson County",
+    "42067": "Juniata County",
+    "42069": "Lackawanna County",
+    "42071": "Lancaster County",
+    "42073": "Lawrence County",
+    "42075": "Lebanon County",
+    "42077": "Lehigh County",
+    "42079": "Luzerne County",
+    "42081": "Lycoming County",
+    "42083": "McKean County",
+    "42085": "Mercer County",
+    "42087": "Mifflin County",
+    "42089": "Monroe County",
+    "42091": "Montgomery County",
+    "42093": "Montour County",
+    "42095": "Northampton County",
+    "42097": "Northumberland County",
+    "42099": "Perry County",
+    "42101": "Philadelphia County",
+    "42103": "Pike County",
+    "42105": "Potter County",
+    "42107": "Schuylkill County",
+    "42109": "Snyder County",
+    "42111": "Somerset County",
+    "42113": "Sullivan County",
+    "42115": "Susquehanna County",
+    "42117": "Tioga County",
+    "42119": "Union County",
+    "42121": "Venango County",
+    "42123": "Warren County",
+    "42125": "Washington County",
+    "42127": "Wayne County",
+    "42129": "Westmoreland County",
+    "42131": "Wyoming County",
+    "42133": "York County",
+    "44001": "Bristol County",
+    "44003": "Kent County",
+    "44005": "Newport County",
+    "44007": "Providence County",
+    "44009": "Washington County",
+    "45001": "Abbeville County",
+    "45003": "Aiken County",
+    "45005": "Allendale County",
+    "45007": "Anderson County",
+    "45009": "Bamberg County",
+    "45011": "Barnwell County",
+    "45013": "Beaufort County",
+    "45015": "Berkeley County",
+    "45017": "Calhoun County",
+    "45019": "Charleston County",
+    "45021": "Cherokee County",
+    "45023": "Chester County",
+    "45025": "Chesterfield County",
+    "45027": "Clarendon County",
+    "45029": "Colleton County",
+    "45031": "Darlington County",
+    "45033": "Dillon County",
+    "45035": "Dorchester County",
+    "45037": "Edgefield County",
+    "45039": "Fairfield County",
+    "45041": "Florence County",
+    "45043": "Georgetown County",
+    "45045": "Greenville County",
+    "45047": "Greenwood County",
+    "45049": "Hampton County",
+    "45051": "Horry County",
+    "45053": "Jasper County",
+    "45055": "Kershaw County",
+    "45057": "Lancaster County",
+    "45059": "Laurens County",
+    "45061": "Lee County",
+    "45063": "Lexington County",
+    "45065": "McCormick County",
+    "45067": "Marion County",
+    "45069": "Marlboro County",
+    "45071": "Newberry County",
+    "45073": "Oconee County",
+    "45075": "Orangeburg County",
+    "45077": "Pickens County",
+    "45079": "Richland County",
+    "45081": "Saluda County",
+    "45083": "Spartanburg County",
+    "45085": "Sumter County",
+    "45087": "Union County",
+    "45089": "Williamsburg County",
+    "45091": "York County",
+    "46003": "Aurora County",
+    "46005": "Beadle County",
+    "46007": "Bennett County",
+    "46009": "Bon Homme County",
+    "46011": "Brookings County",
+    "46013": "Brown County",
+    "46015": "Brule County",
+    "46017": "Buffalo County",
+    "46019": "Butte County",
+    "46021": "Campbell County",
+    "46023": "Charles Mix County",
+    "46025": "Clark County",
+    "46027": "Clay County",
+    "46029": "Codington County",
+    "46031": "Corson County",
+    "46033": "Custer County",
+    "46035": "Davison County",
+    "46037": "Day County",
+    "46039": "Deuel County",
+    "46041": "Dewey County",
+    "46043": "Douglas County",
+    "46045": "Edmunds County",
+    "46047": "Fall River County",
+    "46049": "Faulk County",
+    "46051": "Grant County",
+    "46053": "Gregory County",
+    "46055": "Haakon County",
+    "46057": "Hamlin County",
+    "46059": "Hand County",
+    "46061": "Hanson County",
+    "46063": "Harding County",
+    "46065": "Hughes County",
+    "46067": "Hutchinson County",
+    "46069": "Hyde County",
+    "46071": "Jackson County",
+    "46073": "Jerauld County",
+    "46075": "Jones County",
+    "46077": "Kingsbury County",
+    "46079": "Lake County",
+    "46081": "Lawrence County",
+    "46083": "Lincoln County",
+    "46085": "Lyman County",
+    "46087": "McCook County",
+    "46089": "McPherson County",
+    "46091": "Marshall County",
+    "46093": "Meade County",
+    "46095": "Mellette County",
+    "46097": "Miner County",
+    "46099": "Minnehaha County",
+    "46101": "Moody County",
+    "46102": "Oglala Lakota County",
+    "46103": "Pennington County",
+    "46105": "Perkins County",
+    "46107": "Potter County",
+    "46109": "Roberts County",
+    "46111": "Sanborn County",
+    "46113": "Shannon County",
+    "46115": "Spink County",
+    "46117": "Stanley County",
+    "46119": "Sully County",
+    "46121": "Todd County",
+    "46123": "Tripp County",
+    "46125": "Turner County",
+    "46127": "Union County",
+    "46129": "Walworth County",
+    "46135": "Yankton County",
+    "46137": "Ziebach County",
+    "47001": "Anderson County",
+    "47003": "Bedford County",
+    "47005": "Benton County",
+    "47007": "Bledsoe County",
+    "47009": "Blount County",
+    "47011": "Bradley County",
+    "47013": "Campbell County",
+    "47015": "Cannon County",
+    "47017": "Carroll County",
+    "47019": "Carter County",
+    "47021": "Cheatham County",
+    "47023": "Chester County",
+    "47025": "Claiborne County",
+    "47027": "Clay County",
+    "47029": "Cocke County",
+    "47031": "Coffee County",
+    "47033": "Crockett County",
+    "47035": "Cumberland County",
+    "47037": "Davidson County",
+    "47039": "Decatur County",
+    "47041": "DeKalb County",
+    "47043": "Dickson County",
+    "47045": "Dyer County",
+    "47047": "Fayette County",
+    "47049": "Fentress County",
+    "47051": "Franklin County",
+    "47053": "Gibson County",
+    "47055": "Giles County",
+    "47057": "Grainger County",
+    "47059": "Greene County",
+    "47061": "Grundy County",
+    "47063": "Hamblen County",
+    "47065": "Hamilton County",
+    "47067": "Hancock County",
+    "47069": "Hardeman County",
+    "47071": "Hardin County",
+    "47073": "Hawkins County",
+    "47075": "Haywood County",
+    "47077": "Henderson County",
+    "47079": "Henry County",
+    "47081": "Hickman County",
+    "47083": "Houston County",
+    "47085": "Humphreys County",
+    "47087": "Jackson County",
+    "47089": "Jefferson County",
+    "47091": "Johnson County",
+    "47093": "Knox County",
+    "47095": "Lake County",
+    "47097": "Lauderdale County",
+    "47099": "Lawrence County",
+    "47101": "Lewis County",
+    "47103": "Lincoln County",
+    "47105": "Loudon County",
+    "47107": "McMinn County",
+    "47109": "McNairy County",
+    "47111": "Macon County",
+    "47113": "Madison County",
+    "47115": "Marion County",
+    "47117": "Marshall County",
+    "47119": "Maury County",
+    "47121": "Meigs County",
+    "47123": "Monroe County",
+    "47125": "Montgomery County",
+    "47127": "Moore County",
+    "47129": "Morgan County",
+    "47131": "Obion County",
+    "47133": "Overton County",
+    "47135": "Perry County",
+    "47137": "Pickett County",
+    "47139": "Polk County",
+    "47141": "Putnam County",
+    "47143": "Rhea County",
+    "47145": "Roane County",
+    "47147": "Robertson County",
+    "47149": "Rutherford County",
+    "47151": "Scott County",
+    "47153": "Sequatchie County",
+    "47155": "Sevier County",
+    "47157": "Shelby County",
+    "47159": "Smith County",
+    "47161": "Stewart County",
+    "47163": "Sullivan County",
+    "47165": "Sumner County",
+    "47167": "Tipton County",
+    "47169": "Trousdale County",
+    "47171": "Unicoi County",
+    "47173": "Union County",
+    "47175": "Van Buren County",
+    "47177": "Warren County",
+    "47179": "Washington County",
+    "47181": "Wayne County",
+    "47183": "Weakley County",
+    "47185": "White County",
+    "47187": "Williamson County",
+    "47189": "Wilson County",
+    "48001": "Anderson County",
+    "48003": "Andrews County",
+    "48005": "Angelina County",
+    "48007": "Aransas County",
+    "48009": "Archer County",
+    "48011": "Armstrong County",
+    "48013": "Atascosa County",
+    "48015": "Austin County",
+    "48017": "Bailey County",
+    "48019": "Bandera County",
+    "48021": "Bastrop County",
+    "48023": "Baylor County",
+    "48025": "Bee County",
+    "48027": "Bell County",
+    "48029": "Bexar County",
+    "48031": "Blanco County",
+    "48033": "Borden County",
+    "48035": "Bosque County",
+    "48037": "Bowie County",
+    "48039": "Brazoria County",
+    "48041": "Brazos County",
+    "48043": "Brewster County",
+    "48045": "Briscoe County",
+    "48047": "Brooks County",
+    "48049": "Brown County",
+    "48051": "Burleson County",
+    "48053": "Burnet County",
+    "48055": "Caldwell County",
+    "48057": "Calhoun County",
+    "48059": "Callahan County",
+    "48061": "Cameron County",
+    "48063": "Camp County",
+    "48065": "Carson County",
+    "48067": "Cass County",
+    "48069": "Castro County",
+    "48071": "Chambers County",
+    "48073": "Cherokee County",
+    "48075": "Childress County",
+    "48077": "Clay County",
+    "48079": "Cochran County",
+    "48081": "Coke County",
+    "48083": "Coleman County",
+    "48085": "Collin County",
+    "48087": "Collingsworth County",
+    "48089": "Colorado County",
+    "48091": "Comal County",
+    "48093": "Comanche County",
+    "48095": "Concho County",
+    "48097": "Cooke County",
+    "48099": "Coryell County",
+    "48101": "Cottle County",
+    "48103": "Crane County",
+    "48105": "Crockett County",
+    "48107": "Crosby County",
+    "48109": "Culberson County",
+    "48111": "Dallam County",
+    "48113": "Dallas County",
+    "48115": "Dawson County",
+    "48117": "Deaf Smith County",
+    "48119": "Delta County",
+    "48121": "Denton County",
+    "48123": "DeWitt County",
+    "48125": "Dickens County",
+    "48127": "Dimmit County",
+    "48129": "Donley County",
+    "48131": "Duval County",
+    "48133": "Eastland County",
+    "48135": "Ector County",
+    "48137": "Edwards County",
+    "48139": "Ellis County",
+    "48141": "El Paso County",
+    "48143": "Erath County",
+    "48145": "Falls County",
+    "48147": "Fannin County",
+    "48149": "Fayette County",
+    "48151": "Fisher County",
+    "48153": "Floyd County",
+    "48155": "Foard County",
+    "48157": "Fort Bend County",
+    "48159": "Franklin County",
+    "48161": "Freestone County",
+    "48163": "Frio County",
+    "48165": "Gaines County",
+    "48167": "Galveston County",
+    "48169": "Garza County",
+    "48171": "Gillespie County",
+    "48173": "Glasscock County",
+    "48175": "Goliad County",
+    "48177": "Gonzales County",
+    "48179": "Gray County",
+    "48181": "Grayson County",
+    "48183": "Gregg County",
+    "48185": "Grimes County",
+    "48187": "Guadalupe County",
+    "48189": "Hale County",
+    "48191": "Hall County",
+    "48193": "Hamilton County",
+    "48195": "Hansford County",
+    "48197": "Hardeman County",
+    "48199": "Hardin County",
+    "48201": "Harris County",
+    "48203": "Harrison County",
+    "48205": "Hartley County",
+    "48207": "Haskell County",
+    "48209": "Hays County",
+    "48211": "Hemphill County",
+    "48213": "Henderson County",
+    "48215": "Hidalgo County",
+    "48217": "Hill County",
+    "48219": "Hockley County",
+    "48221": "Hood County",
+    "48223": "Hopkins County",
+    "48225": "Houston County",
+    "48227": "Howard County",
+    "48229": "Hudspeth County",
+    "48231": "Hunt County",
+    "48233": "Hutchinson County",
+    "48235": "Irion County",
+    "48237": "Jack County",
+    "48239": "Jackson County",
+    "48241": "Jasper County",
+    "48243": "Jeff Davis County",
+    "48245": "Jefferson County",
+    "48247": "Jim Hogg County",
+    "48249": "Jim Wells County",
+    "48251": "Johnson County",
+    "48253": "Jones County",
+    "48255": "Karnes County",
+    "48257": "Kaufman County",
+    "48259": "Kendall County",
+    "48261": "Kenedy County",
+    "48263": "Kent County",
+    "48265": "Kerr County",
+    "48267": "Kimble County",
+    "48269": "King County",
+    "48271": "Kinney County",
+    "48273": "Kleberg County",
+    "48275": "Knox County",
+    "48277": "Lamar County",
+    "48279": "Lamb County",
+    "48281": "Lampasas County",
+    "48283": "La Salle County",
+    "48285": "Lavaca County",
+    "48287": "Lee County",
+    "48289": "Leon County",
+    "48291": "Liberty County",
+    "48293": "Limestone County",
+    "48295": "Lipscomb County",
+    "48297": "Live Oak County",
+    "48299": "Llano County",
+    "48301": "Loving County",
+    "48303": "Lubbock County",
+    "48305": "Lynn County",
+    "48307": "McCulloch County",
+    "48309": "McLennan County",
+    "48311": "McMullen County",
+    "48313": "Madison County",
+    "48315": "Marion County",
+    "48317": "Martin County",
+    "48319": "Mason County",
+    "48321": "Matagorda County",
+    "48323": "Maverick County",
+    "48325": "Medina County",
+    "48327": "Menard County",
+    "48329": "Midland County",
+    "48331": "Milam County",
+    "48333": "Mills County",
+    "48335": "Mitchell County",
+    "48337": "Montague County",
+    "48339": "Montgomery County",
+    "48341": "Moore County",
+    "48343": "Morris County",
+    "48345": "Motley County",
+    "48347": "Nacogdoches County",
+    "48349": "Navarro County",
+    "48351": "Newton County",
+    "48353": "Nolan County",
+    "48355": "Nueces County",
+    "48357": "Ochiltree County",
+    "48359": "Oldham County",
+    "48361": "Orange County",
+    "48363": "Palo Pinto County",
+    "48365": "Panola County",
+    "48367": "Parker County",
+    "48369": "Parmer County",
+    "48371": "Pecos County",
+    "48373": "Polk County",
+    "48375": "Potter County",
+    "48377": "Presidio County",
+    "48379": "Rains County",
+    "48381": "Randall County",
+    "48383": "Reagan County",
+    "48385": "Real County",
+    "48387": "Red River County",
+    "48389": "Reeves County",
+    "48391": "Refugio County",
+    "48393": "Roberts County",
+    "48395": "Robertson County",
+    "48397": "Rockwall County",
+    "48399": "Runnels County",
+    "48401": "Rusk County",
+    "48403": "Sabine County",
+    "48405": "San Augustine County",
+    "48407": "San Jacinto County",
+    "48409": "San Patricio County",
+    "48411": "San Saba County",
+    "48413": "Schleicher County",
+    "48415": "Scurry County",
+    "48417": "Shackelford County",
+    "48419": "Shelby County",
+    "48421": "Sherman County",
+    "48423": "Smith County",
+    "48425": "Somervell County",
+    "48427": "Starr County",
+    "48429": "Stephens County",
+    "48431": "Sterling County",
+    "48433": "Stonewall County",
+    "48435": "Sutton County",
+    "48437": "Swisher County",
+    "48439": "Tarrant County",
+    "48441": "Taylor County",
+    "48443": "Terrell County",
+    "48445": "Terry County",
+    "48447": "Throckmorton County",
+    "48449": "Titus County",
+    "48451": "Tom Green County",
+    "48453": "Travis County",
+    "48455": "Trinity County",
+    "48457": "Tyler County",
+    "48459": "Upshur County",
+    "48461": "Upton County",
+    "48463": "Uvalde County",
+    "48465": "Val Verde County",
+    "48467": "Van Zandt County",
+    "48469": "Victoria County",
+    "48471": "Walker County",
+    "48473": "Waller County",
+    "48475": "Ward County",
+    "48477": "Washington County",
+    "48479": "Webb County",
+    "48481": "Wharton County",
+    "48483": "Wheeler County",
+    "48485": "Wichita County",
+    "48487": "Wilbarger County",
+    "48489": "Willacy County",
+    "48491": "Williamson County",
+    "48493": "Wilson County",
+    "48495": "Winkler County",
+    "48497": "Wise County",
+    "48499": "Wood County",
+    "48501": "Yoakum County",
+    "48503": "Young County",
+    "48505": "Zapata County",
+    "48507": "Zavala County",
+    "49001": "Beaver County",
+    "49003": "Box Elder County",
+    "49005": "Cache County",
+    "49007": "Carbon County",
+    "49009": "Daggett County",
+    "49011": "Davis County",
+    "49013": "Duchesne County",
+    "49015": "Emery County",
+    "49017": "Garfield County",
+    "49019": "Grand County",
+    "49021": "Iron County",
+    "49023": "Juab County",
+    "49025": "Kane County",
+    "49027": "Millard County",
+    "49029": "Morgan County",
+    "49031": "Piute County",
+    "49033": "Rich County",
+    "49035": "Salt Lake County",
+    "49037": "San Juan County",
+    "49039": "Sanpete County",
+    "49041": "Sevier County",
+    "49043": "Summit County",
+    "49045": "Tooele County",
+    "49047": "Uintah County",
+    "49049": "Utah County",
+    "49051": "Wasatch County",
+    "49053": "Washington County",
+    "49055": "Wayne County",
+    "49057": "Weber County",
+    "50001": "Addison County",
+    "50003": "Bennington County",
+    "50005": "Caledonia County",
+    "50007": "Chittenden County",
+    "50009": "Essex County",
+    "50011": "Franklin County",
+    "50013": "Grand Isle County",
+    "50015": "Lamoille County",
+    "50017": "Orange County",
+    "50019": "Orleans County",
+    "50021": "Rutland County",
+    "50023": "Washington County",
+    "50025": "Windham County",
+    "50027": "Windsor County",
+    "51001": "Accomack County",
+    "51003": "Albemarle County",
+    "51005": "Alleghany County",
+    "51007": "Amelia County",
+    "51009": "Amherst County",
+    "51011": "Appomattox County",
+    "51013": "Arlington County",
+    "51015": "Augusta County",
+    "51017": "Bath County",
+    "51019": "Bedford County",
+    "51021": "Bland County",
+    "51023": "Botetourt County",
+    "51025": "Brunswick County",
+    "51027": "Buchanan County",
+    "51029": "Buckingham County",
+    "51031": "Campbell County",
+    "51033": "Caroline County",
+    "51035": "Carroll County",
+    "51036": "Charles City County",
+    "51037": "Charlotte County",
+    "51041": "Chesterfield County",
+    "51043": "Clarke County",
+    "51045": "Craig County",
+    "51047": "Culpeper County",
+    "51049": "Cumberland County",
+    "51051": "Dickenson County",
+    "51053": "Dinwiddie County",
+    "51057": "Essex County",
+    "51059": "Fairfax County",
+    "51061": "Fauquier County",
+    "51063": "Floyd County",
+    "51065": "Fluvanna County",
+    "51067": "Franklin County",
+    "51069": "Frederick County",
+    "51071": "Giles County",
+    "51073": "Gloucester County",
+    "51075": "Goochland County",
+    "51077": "Grayson County",
+    "51079": "Greene County",
+    "51081": "Greensville County",
+    "51083": "Halifax County",
+    "51085": "Hanover County",
+    "51087": "Henrico County",
+    "51089": "Henry County",
+    "51091": "Highland County",
+    "51093": "Isle of Wight County",
+    "51095": "James City County",
+    "51097": "King and Queen County",
+    "51099": "King George County",
+    "51101": "King William County",
+    "51103": "Lancaster County",
+    "51105": "Lee County",
+    "51107": "Loudoun County",
+    "51109": "Louisa County",
+    "51111": "Lunenburg County",
+    "51113": "Madison County",
+    "51115": "Mathews County",
+    "51117": "Mecklenburg County",
+    "51119": "Middlesex County",
+    "51121": "Montgomery County",
+    "51125": "Nelson County",
+    "51127": "New Kent County",
+    "51131": "Northampton County",
+    "51133": "Northumberland County",
+    "51135": "Nottoway County",
+    "51137": "Orange County",
+    "51139": "Page County",
+    "51141": "Patrick County",
+    "51143": "Pittsylvania County",
+    "51145": "Powhatan County",
+    "51147": "Prince Edward County",
+    "51149": "Prince George County",
+    "51153": "Prince William County",
+    "51155": "Pulaski County",
+    "51157": "Rappahannock County",
+    "51159": "Richmond County",
+    "51161": "Roanoke County",
+    "51163": "Rockbridge County",
+    "51165": "Rockingham County",
+    "51167": "Russell County",
+    "51169": "Scott County",
+    "51171": "Shenandoah County",
+    "51173": "Smyth County",
+    "51175": "Southampton County",
+    "51177": "Spotsylvania County",
+    "51179": "Stafford County",
+    "51181": "Surry County",
+    "51183": "Sussex County",
+    "51185": "Tazewell County",
+    "51187": "Warren County",
+    "51191": "Washington County",
+    "51193": "Westmoreland County",
+    "51195": "Wise County",
+    "51197": "Wythe County",
+    "51199": "York County",
+    "51510": "Alexandria City",
+    "51520": "Bristol City",
+    "51530": "Buena Vista City",
+    "51540": "Charlottesville City",
+    "51550": "Chesapeake City",
+    "51560": "Clifton Forge City",
+    "51570": "Colonial Heights City",
+    "51580": "Covington City",
+    "51590": "Danville City",
+    "51595": "Emporia City",
+    "51600": "Fairfax City",
+    "51610": "Falls Church City",
+    "51620": "Franklin City",
+    "51630": "Fredericksburg City",
+    "51640": "Galax City",
+    "51650": "Hampton City",
+    "51660": "Harrisonburg City",
+    "51670": "Hopewell City",
+    "51678": "Lexington City",
+    "51680": "Lynchburg City",
+    "51683": "Manassas City",
+    "51685": "Manassas Park City",
+    "51690": "Martinsville City",
+    "51700": "Newport News City",
+    "51710": "Norfolk City",
+    "51720": "Norton City",
+    "51730": "Petersburg City",
+    "51735": "Poquoson City",
+    "51740": "Portsmouth City",
+    "51750": "Radford City",
+    "51760": "Richmond City",
+    "51770": "Roanoke City",
+    "51775": "Salem City",
+    "51780": "South Boston City",
+    "51790": "Staunton City",
+    "51800": "Suffolk City",
+    "51810": "Virginia Beach City",
+    "51820": "Waynesboro City",
+    "51830": "Williamsburg City",
+    "51840": "Winchester City",
+    "53001": "Adams County",
+    "53003": "Asotin County",
+    "53005": "Benton County",
+    "53007": "Chelan County",
+    "53009": "Clallam County",
+    "53011": "Clark County",
+    "53013": "Columbia County",
+    "53015": "Cowlitz County",
+    "53017": "Douglas County",
+    "53019": "Ferry County",
+    "53021": "Franklin County",
+    "53023": "Garfield County",
+    "53025": "Grant County",
+    "53027": "Grays Harbor County",
+    "53029": "Island County",
+    "53031": "Jefferson County",
+    "53033": "King County",
+    "53035": "Kitsap County",
+    "53037": "Kittitas County",
+    "53039": "Klickitat County",
+    "53041": "Lewis County",
+    "53043": "Lincoln County",
+    "53045": "Mason County",
+    "53047": "Okanogan County",
+    "53049": "Pacific County",
+    "53051": "Pend Oreille County",
+    "53053": "Pierce County",
+    "53055": "San Juan County",
+    "53057": "Skagit County",
+    "53059": "Skamania County",
+    "53061": "Snohomish County",
+    "53063": "Spokane County",
+    "53065": "Stevens County",
+    "53067": "Thurston County",
+    "53069": "Wahkiakum County",
+    "53071": "Walla Walla County",
+    "53073": "Whatcom County",
+    "53075": "Whitman County",
+    "53077": "Yakima County",
+    "54001": "Barbour County",
+    "54003": "Berkeley County",
+    "54005": "Boone County",
+    "54007": "Braxton County",
+    "54009": "Brooke County",
+    "54011": "Cabell County",
+    "54013": "Calhoun County",
+    "54015": "Clay County",
+    "54017": "Doddridge County",
+    "54019": "Fayette County",
+    "54021": "Gilmer County",
+    "54023": "Grant County",
+    "54025": "Greenbrier County",
+    "54027": "Hampshire County",
+    "54029": "Hancock County",
+    "54031": "Hardy County",
+    "54033": "Harrison County",
+    "54035": "Jackson County",
+    "54037": "Jefferson County",
+    "54039": "Kanawha County",
+    "54041": "Lewis County",
+    "54043": "Lincoln County",
+    "54045": "Logan County",
+    "54047": "McDowell County",
+    "54049": "Marion County",
+    "54051": "Marshall County",
+    "54053": "Mason County",
+    "54055": "Mercer County",
+    "54057": "Mineral County",
+    "54059": "Mingo County",
+    "54061": "Monongalia County",
+    "54063": "Monroe County",
+    "54065": "Morgan County",
+    "54067": "Nicholas County",
+    "54069": "Ohio County",
+    "54071": "Pendleton County",
+    "54073": "Pleasants County",
+    "54075": "Pocahontas County",
+    "54077": "Preston County",
+    "54079": "Putnam County",
+    "54081": "Raleigh County",
+    "54083": "Randolph County",
+    "54085": "Ritchie County",
+    "54087": "Roane County",
+    "54089": "Summers County",
+    "54091": "Taylor County",
+    "54093": "Tucker County",
+    "54095": "Tyler County",
+    "54097": "Upshur County",
+    "54099": "Wayne County",
+    "54101": "Webster County",
+    "54103": "Wetzel County",
+    "54105": "Wirt County",
+    "54107": "Wood County",
+    "54109": "Wyoming County",
+    "55001": "Adams County",
+    "55003": "Ashland County",
+    "55005": "Barron County",
+    "55007": "Bayfield County",
+    "55009": "Brown County",
+    "55011": "Buffalo County",
+    "55013": "Burnett County",
+    "55015": "Calumet County",
+    "55017": "Chippewa County",
+    "55019": "Clark County",
+    "55021": "Columbia County",
+    "55023": "Crawford County",
+    "55025": "Dane County",
+    "55027": "Dodge County",
+    "55029": "Door County",
+    "55031": "Douglas County",
+    "55033": "Dunn County",
+    "55035": "Eau Claire County",
+    "55037": "Florence County",
+    "55039": "Fond du Lac County",
+    "55041": "Forest County",
+    "55043": "Grant County",
+    "55045": "Green County",
+    "55047": "Green Lake County",
+    "55049": "Iowa County",
+    "55051": "Iron County",
+    "55053": "Jackson County",
+    "55055": "Jefferson County",
+    "55057": "Juneau County",
+    "55059": "Kenosha County",
+    "55061": "Kewaunee County",
+    "55063": "La Crosse County",
+    "55065": "Lafayette County",
+    "55067": "Langlade County",
+    "55069": "Lincoln County",
+    "55071": "Manitowoc County",
+    "55073": "Marathon County",
+    "55075": "Marinette County",
+    "55077": "Marquette County",
+    "55078": "Menominee County",
+    "55079": "Milwaukee County",
+    "55081": "Monroe County",
+    "55083": "Oconto County",
+    "55085": "Oneida County",
+    "55087": "Outagamie County",
+    "55089": "Ozaukee County",
+    "55091": "Pepin County",
+    "55093": "Pierce County",
+    "55095": "Polk County",
+    "55097": "Portage County",
+    "55099": "Price County",
+    "55101": "Racine County",
+    "55103": "Richland County",
+    "55105": "Rock County",
+    "55107": "Rusk County",
+    "55109": "St. Croix County",
+    "55111": "Sauk County",
+    "55113": "Sawyer County",
+    "55115": "Shawano County",
+    "55117": "Sheboygan County",
+    "55119": "Taylor County",
+    "55121": "Trempealeau County",
+    "55123": "Vernon County",
+    "55125": "Vilas County",
+    "55127": "Walworth County",
+    "55129": "Washburn County",
+    "55131": "Washington County",
+    "55133": "Waukesha County",
+    "55135": "Waupaca County",
+    "55137": "Waushara County",
+    "55139": "Winnebago County",
+    "55141": "Wood County",
+    "56001": "Albany County",
+    "56003": "Big Horn County",
+    "56005": "Campbell County",
+    "56007": "Carbon County",
+    "56009": "Converse County",
+    "56011": "Crook County",
+    "56013": "Fremont County",
+    "56015": "Goshen County",
+    "56017": "Hot Springs County",
+    "56019": "Johnson County",
+    "56021": "Laramie County",
+    "56023": "Lincoln County",
+    "56025": "Natrona County",
+    "56027": "Niobrara County",
+    "56029": "Park County",
+    "56031": "Platte County",
+    "56033": "Sheridan County",
+    "56035": "Sublette County",
+    "56037": "Sweetwater County",
+    "56039": "Teton County",
+    "56041": "Uinta County",
+    "56043": "Washakie County",
+    "56045": "Weston County",
+    "60010": "Eastern District",
+    "60020": "Manu'a District",
+    "60030": "Rose Island",
+    "60040": "Swains Island",
+    "60050": "Western District",
+    "66010": "Guam",
+    "69085": "Northern Islands Municipality",
+    "69100": "Rota Municipality",
+    "69110": "Saipan Municipality",
+    "69120": "Tinian Municipality",
+    "72001": "Adjuntas Municipio",
+    "72003": "Aguada Municipio",
+    "72005": "Aguadilla Municipio",
+    "72007": "Aguas Buenas Municipio",
+    "72009": "Aibonito Municipio",
+    "72011": "Anasco Municipio",
+    "72013": "Arecibo Municipio",
+    "72015": "Arroyo Municipio",
+    "72017": "Barceloneta Municipio",
+    "72019": "Barranquitas Municipio",
+    "72021": "Bayamon Municipio",
+    "72023": "Cabo Rojo Municipio",
+    "72025": "Caguas Municipio",
+    "72027": "Camuy Municipio",
+    "72029": "Canovanas Municipio",
+    "72031": "Carolina Municipio",
+    "72033": "Catano Municipio",
+    "72035": "Cayey Municipio",
+    "72037": "Ceiba Municipio",
+    "72039": "Ciales Municipio",
+    "72041": "Cidra Municipio",
+    "72043": "Coamo Municipio",
+    "72045": "Comerio Municipio",
+    "72047": "Corozal Municipio",
+    "72049": "Culebra Municipio",
+    "72051": "Dorado Municipio",
+    "72053": "Fajardo Municipio",
+    "72054": "Florida Municipio",
+    "72055": "Guanica Municipio",
+    "72057": "Guayama Municipio",
+    "72059": "Guayanilla Municipio",
+    "72061": "Guaynabo Municipio",
+    "72063": "Gurabo Municipio",
+    "72065": "Hatillo Municipio",
+    "72067": "Hormigueros Municipio",
+    "72069": "Humacao Municipio",
+    "72071": "Isabela Municipio",
+    "72073": "Jayuya Municipio",
+    "72075": "Juana Diaz Municipio",
+    "72077": "Juncos Municipio",
+    "72079": "Lajas Municipio",
+    "72081": "Lares Municipio",
+    "72083": "Las Marias Municipio",
+    "72085": "Las Piedras Municipio",
+    "72087": "Loiza Municipio",
+    "72089": "Luquillo Municipio",
+    "72091": "Manati Municipio",
+    "72093": "Maricao Municipio",
+    "72095": "Maunabo Municipio",
+    "72097": "Mayaquez Municipio",
+    "72099": "Moca Municipio",
+    "72101": "Morovis Municipio",
+    "72103": "Naguabo Municipio",
+    "72105": "Naranjito Municipio",
+    "72107": "Orocovis Municipio",
+    "72109": "Patillas Municipio",
+    "72111": "Penuelas Municipio",
+    "72113": "Ponce Municipio",
+    "72115": "Quebradillas Municipio",
+    "72117": "Rincon Municipio",
+    "72119": "Rio Grande Municipio",
+    "72121": "Sabana Grande Municipio",
+    "72123": "Salinas Municipio",
+    "72125": "San German Municipio",
+    "72127": "San Juan Municipio",
+    "72129": "San Lorenzo Municipio",
+    "72131": "San Sebastian Municipio",
+    "72133": "Santa Isabel Municipio",
+    "72135": "Toa Alta Municipio",
+    "72137": "Toa Baja Municipio",
+    "72139": "Trujillo Alto Municipio",
+    "72141": "Utuado Municipio",
+    "72143": "Vega Alta Municipio",
+    "72145": "Vega Baja Municipio",
+    "72147": "Vieques Municipio",
+    "72149": "Villalba Municipio",
+    "72151": "Yabucoa Municipio",
+    "72153": "Yauco Municipio",
+    "78010": "St. Croix Island",
+    "78020": "St. John Island",
+    "78030": "St. Thomas Island",
+}
diff --git a/dataretrieval/codes/counties.py b/dataretrieval/codes/counties.py
new file mode 100644
index 00000000..96d22463
--- /dev/null
+++ b/dataretrieval/codes/counties.py
@@ -0,0 +1,266 @@
+"""County code lookups and normalization, keyed by five-digit FIPS code.
+
+``counties`` maps each county or county equivalent -- parish, borough, census
+area, independent city, municipio, Connecticut planning region -- to its name
+as the Water Data API spells it (e.g. ``"55025": "Dane County"``).
+:func:`to_county` normalizes a county identifier to a chosen representation,
+and :func:`apply_county` resolves a getter's ``county`` argument into the
+parameters its service filters on. An unrecognized value raises
+``ValueError``.
+
+Coverage matches :mod:`dataretrieval.codes.states`: the 50 states, the
+District of Columbia, and the five US territories. The table is a snapshot of
+the Water Data ``counties`` collection, which follows the Census Bureau's
+current codes; ``tests/utils_test.py`` compares the two live.
+"""
+
+from __future__ import annotations
+
+import difflib
+from collections.abc import Callable, Iterable
+from typing import Any
+
+from dataretrieval._validation import reject_together, require_one_of
+
+from ._county_table import counties
+from .states import to_state
+
+__all__ = ["apply_county", "counties", "to_county"]
+
+#: Trailing words that name a county's kind rather than the county, longest
+#: first so "City and Borough" is stripped before "Borough". A caller may omit
+#: them: ``"Dane"`` matches ``"Dane County"`` when nothing else in the state
+#: shares the base name.
+_DESIGNATIONS = (
+    "city and borough",
+    "planning region",
+    "census area",
+    "municipality",
+    "municipio",
+    "borough",
+    "county",
+    "parish",
+    "island",
+    "district",
+    "city",
+)
+
+_FORMATS = ("fips", "fips_us", "name")
+
+
+def to_county(
+    value: str | int | Iterable[str | int],
+    to: str = "fips",
+    *,
+    state: str | int | Iterable[str | int] | None = None,
+) -> str | list[str]:
+    """Normalize a US county identifier to a chosen representation.
+
+    ``value`` may be given as
+
+    * a five-digit FIPS code, as a string or integer (``"55025"``, ``55025``);
+    * a ``US:``-prefixed code with a colon between state and county
+      (``"US:55:025"``), as the Water Data statistics service writes it;
+    * with ``state``, a three-digit county code (``"025"``) or a name, matched
+      case-insensitively, with or without its designation (``"Dane County"``
+      or ``"Dane"``).
+
+    County names and three-digit codes repeat across states, so those forms
+    need ``state``, which takes any form :func:`~dataretrieval.codes.states.to_state`
+    accepts. A full FIPS code already names its state; given both, they must
+    agree. An iterable is resolved element-wise to a list.
+
+    ``to`` selects the output representation:
+
+    * ``"fips"``    -> five-digit FIPS code, e.g. ``"55025"``
+    * ``"fips_us"`` -> ``"US:"`` + state + ``":"`` + county, e.g. ``"US:55:025"``
+    * ``"name"``    -> the county's name, e.g. ``"Dane County"``
+
+    Raises
+    ------
+    ValueError
+        If a value is not a county in the table, a name or three-digit code
+        has no ``state``, a bare name matches more than one county in the
+        state, or a FIPS code lies outside ``state``.
+    """
+    require_one_of(to, _FORMATS, name="to")
+    state_fips = None if state is None else _single_state_fips(state)
+    if isinstance(value, (str, int)):
+        return _format_county(_to_fips_one(value, state_fips), to)
+    return [_format_county(_to_fips_one(v, state_fips), to) for v in value]
+
+
+def apply_county(
+    local_vars: dict[str, Any],
+    *,
+    render: Callable[[list[str]], dict[str, Any]],
+    reject: tuple[str, ...],
+) -> dict[str, Any]:
+    """Resolve a getter's ``county`` argument into its service's parameters.
+
+    Pops ``county`` from ``local_vars`` (a no-op when absent) together with
+    ``state``, which then qualifies the counties instead of filtering on its
+    own: a county lies in one state, so sending both would be redundant at
+    best. The counties are resolved to five-digit FIPS codes, deduplicated in
+    order, and passed to ``render`` as a list, which returns the parameters
+    this service filters on; they are merged into ``local_vars``, which is
+    returned.
+
+    ``reject`` names the getter's native state and county parameters. Passing
+    ``county`` with any of them raises ``ValueError``, and an unrecognized
+    county is re-raised naming them as the way to send the service's own
+    value. ``render`` may raise ``ValueError`` for a county its service cannot
+    filter on.
+    """
+    county = local_vars.pop("county", None)
+    if county is None:
+        return local_vars
+    state = local_vars.pop("state", None)
+    reject_together(
+        {"county": county, **{p: local_vars.get(p) for p in reject}},
+        context="they filter on the same thing",
+    )
+    try:
+        fips = to_county(county, "fips", state=state)
+    except ValueError as err:
+        raise ValueError(
+            f"{err} Or pass {' or '.join(reject)} directly, using the API's "
+            "native value."
+        ) from err
+    local_vars.update(render(list(dict.fromkeys(_as_list(fips)))))
+    return local_vars
+
+
+def _as_list(value: str | list[str]) -> list[str]:
+    """``to_county``'s result as a list, whether it was given one value or many."""
+    return value if isinstance(value, list) else [value]
+
+
+def _single_state_fips(state: object) -> str:
+    """The two-digit FIPS code of the one state qualifying ``county``."""
+    if not isinstance(state, (str, int)):
+        raise ValueError(
+            "With county, state names the one state the counties are in, so it "
+            f"must be a single state (got {state!r}). To select counties in "
+            "several states, pass each as a five-digit FIPS code, e.g. "
+            "county=['55025', '17031'], without state."
+        )
+    fips = to_state(state, "fips")
+    assert isinstance(fips, str)
+    return fips
+
+
+def _to_fips_one(value: str | int, state_fips: str | None) -> str:
+    """Resolve one county identifier to its five-digit FIPS code."""
+    if isinstance(value, bool):
+        raise _unrecognized(value)
+    s = str(value).strip()
+    fips = _parse_code(s, state_fips)
+    if fips is None:
+        if state_fips is None:
+            raise ValueError(
+                f"county={value!r} is a name, and county names repeat across "
+                f"states. Pass the state too, e.g. county={value!r}, state='WI', "
+                "or a five-digit FIPS code, e.g. county='55025'."
+            )
+        fips = _match_name(s, state_fips)
+    if fips not in counties:
+        raise _unrecognized(value, in_connecticut=fips.startswith("09"))
+    if state_fips is not None and fips[:2] != state_fips:
+        raise ValueError(
+            f"county={value!r} is in {to_state(fips[:2], 'name')}, not "
+            f"{to_state(state_fips, 'name')}. Drop state, or pass a county in "
+            "that state."
+        )
+    return fips
+
+
+def _parse_code(s: str, state_fips: str | None) -> str | None:
+    """The FIPS code a code-shaped identifier spells, or ``None`` for a name.
+
+    Not checked against the table; the caller does that once for every form.
+    """
+    if s[:3].upper() == "US:":
+        return s[3:].replace(":", "")
+    if not s.isdigit():
+        return None
+    if len(s) == 3 and state_fips is not None:
+        return state_fips + s
+    # An integer, or a string that lost its leading zero (``1001``). Any other
+    # length is returned as given, so the table lookup rejects it.
+    return s.zfill(5) if len(s) == 4 else s
+
+
+def _normal(name: str) -> str:
+    """``name`` lower-cased, without periods, with single spaces: ``"St Louis"``
+    and ``"st. louis"`` compare equal."""
+    return " ".join(name.lower().replace(".", "").split())
+
+
+def _base(name: str) -> str:
+    """``name`` normalized, without its trailing designation."""
+    lowered = _normal(name)
+    for word in _DESIGNATIONS:
+        if lowered.endswith(f" {word}"):
+            return lowered[: -len(word) - 1]
+    return lowered
+
+
+def _match_name(name: str, state_fips: str) -> str:
+    """The FIPS code of the county called ``name`` in the state."""
+    in_state = {f: n for f, n in counties.items() if f[:2] == state_fips}
+    wanted = _normal(name)
+    by_name = {_normal(n): f for f, n in in_state.items()}
+    if wanted in by_name:
+        return by_name[wanted]
+    # The input may itself end in a designation word that is part of the
+    # name ("Charles City" for Charles City County), so try it both ways.
+    keys = {wanted, _base(wanted)}
+    by_base = [f for f, n in in_state.items() if _base(n) in keys]
+    if len(by_base) == 1:
+        return by_base[0]
+    state_name = to_state(state_fips, "name")
+    if by_base:
+        options = ", ".join(repr(in_state[f]) for f in by_base)
+        raise ValueError(
+            f"county={name!r} matches more than one county in {state_name}: "
+            f"{options}. Pass the full name."
+        )
+    raise ValueError(
+        f"county={name!r} is not a county in {state_name}."
+        f"{_suggest(wanted, in_state.values())}"
+    )
+
+
+def _suggest(wanted: str, names: Iterable[str]) -> str:
+    """A "Did you mean" hint naming the counties closest to ``wanted``."""
+    bases: dict[str, list[str]] = {}
+    for n in names:
+        bases.setdefault(_base(n), []).append(n)
+    close = difflib.get_close_matches(_base(wanted), list(bases))
+    suggestions = [repr(n) for c in close for n in bases[c]]
+    return f" Did you mean {', '.join(suggestions)}?" if suggestions else ""
+
+
+def _unrecognized(value: object, *, in_connecticut: bool = False) -> ValueError:
+    """The error for a code that names no county in the table."""
+    hint = (
+        " Connecticut's counties were replaced in 2022 by planning regions, "
+        "codes 09110 to 09190."
+        if in_connecticut
+        else ""
+    )
+    return ValueError(
+        f"{value!r} is not a recognized US county or county equivalent. Pass a "
+        "five-digit FIPS code (county='55025'), or a name with its state "
+        f"(county='Dane County', state='WI').{hint}"
+    )
+
+
+def _format_county(fips: str, to: str) -> str:
+    """Render a five-digit FIPS code in the ``to`` representation."""
+    if to == "fips":
+        return fips
+    if to == "fips_us":
+        return f"US:{fips[:2]}:{fips[2:]}"
+    return counties[fips]
diff --git a/dataretrieval/codes/states.py b/dataretrieval/codes/states.py
index e0d828d2..ea32ccad 100644
--- a/dataretrieval/codes/states.py
+++ b/dataretrieval/codes/states.py
@@ -72,7 +72,7 @@
     "Guam": "gu",
     "Northern Mariana Islands": "mp",
     "Puerto Rico": "pr",
-    "US Virgin Islands": "vi",
+    "Virgin Islands": "vi",
 }
 
 fips_codes = {
@@ -131,7 +131,7 @@
     "Guam": "66",
     "Northern Mariana Islands": "69",
     "Puerto Rico": "72",
-    "US Virgin Islands": "78",
+    "Virgin Islands": "78",
 }
 
 # Reverse lookups (built once): postal code -> name, FIPS code -> name, and a
@@ -140,6 +140,9 @@
 _name_by_postal = {code: name for name, code in state_codes.items()}
 _name_by_fips = {fips: name for name, fips in fips_codes.items()}
 _name_by_lower = {name.lower(): name for name in state_codes}
+# The table names each state as the Water Data and NGWMN ``state_name`` fields
+# do. "US Virgin Islands" is the Census Bureau's name, accepted as input only.
+_name_by_lower["us virgin islands"] = "Virgin Islands"
 
 
 def to_state(
diff --git a/dataretrieval/ngwmn.py b/dataretrieval/ngwmn.py
index ced8cc79..86bc5f75 100644
--- a/dataretrieval/ngwmn.py
+++ b/dataretrieval/ngwmn.py
@@ -24,7 +24,8 @@
 import pandas as pd
 
 from dataretrieval import configuration as _configuration
-from dataretrieval.codes.states import apply_state
+from dataretrieval.codes.counties import apply_county, counties
+from dataretrieval.codes.states import apply_state, to_state
 from dataretrieval.configuration import (
     BaseConfiguration,
     _Chunked,
@@ -80,11 +81,50 @@
 # (there is no service-specific id name as there is for the main collections).
 _NGWMN_OUTPUT_ID = "id"
 
-# NGWMN's request shape matches the generic OGC default (no CQL2-only or
-# date-only collections), but its result columns need their own coercion and
-# sort vocabulary: water-level observations are timestamped by ``sample_time``
-# (not the Water Data ``time``) and report depths/levels in feet.
+# --- county-filter shim ------------------------------------------------------
+# ``sites`` files a county under ``state_name`` and ``county_name``. Its names
+# are the Water Data ``counties`` names that ``codes.counties`` holds, with two
+# exceptions: Anchorage is named the other way round, and Connecticut sites
+# keep the eight counties the state replaced in 2022 with planning regions,
+# which do not map one to one onto them.
+# ``tests/ngwmn_test.py::test_county_names_still_match_the_table_upstream`` fails
+# if that changes.
+_NGWMN_COUNTY_NAMES = {"02020": "Municipality of Anchorage"}
+_LEGACY_COUNTY_STATES = frozenset({"09"})
+
+
+def _sites_county_params(fips: list[str]) -> dict[str, Any]:
+    """``state_name`` plus ``county_name`` for counties in one state."""
+    states = sorted({f[:2] for f in fips})
+    if len(states) > 1:
+        # A cross-state set needs the pairs OR-ed, which NGWMN's edge refuses as
+        # a CQL text filter (HTTP 403); separate state_name and county_name
+        # lists would also match a same-named county in another listed state.
+        raise ValueError(
+            "ngwmn.get_sites takes counties from one state per call, but county "
+            f"names counties in {len(states)} states. Call get_sites once per "
+            "state and concatenate the results."
+        )
+    if states[0] in _LEGACY_COUNTY_STATES:
+        raise ValueError(
+            f"NGWMN still files {to_state(states[0], 'name')} sites under the "
+            "counties it replaced in 2022, which no planning region code "
+            "matches. Pass county_name directly, e.g. county_name='Hartford "
+            f"County', state={to_state(states[0], 'postal')!r}."
+        )
+    return {
+        "state_name": to_state(states[0], "name"),
+        "county_name": [_NGWMN_COUNTY_NAMES.get(f, counties[f]) for f in fips],
+    }
+
+
+# NGWMN has no date-only collections. ``sites`` takes multi-value filters as a
+# CQL2 POST: a comma-joined ``county_name`` matches nothing, where the same
+# names POSTed match. Its result columns need their own coercion and sort
+# vocabulary: water-level observations are timestamped by ``sample_time`` (not
+# the Water Data ``time``) and report depths/levels in feet.
 NGWMN_DIALECT = OgcDialect(
+    cql2_services=frozenset({"sites"}),
     time_cols=frozenset({"sample_time"}),
     numerical_cols=frozenset(
         {
@@ -103,6 +143,8 @@ def _get(service: str, local_vars: dict[str, Any]) -> tuple[pd.DataFrame, BaseMe
     Every NGWMN getter ends with this same call; centralizing it keeps the
     NGWMN base URL, output id, and dialect set in one place.
     """
+    if service == "sites":
+        apply_county(local_vars, render=_sites_county_params, reject=("county_name",))
     queryable = _STATE_QUERYABLE.get(service)
     if queryable is not None:
         apply_state(local_vars, to=queryable["to"], into=queryable["into"])
@@ -131,6 +173,7 @@ def get_sites(
     country_code: str | Iterable[str] | None = None,
     country_name: str | Iterable[str] | None = None,
     state: str | Iterable[str] | None = None,
+    county: str | int | Iterable[str | int] | None = None,
     county_name: str | Iterable[str] | None = None,
     aquifer_name: str | Iterable[str] | None = None,
     site_type: str | Iterable[str] | None = None,
@@ -178,8 +221,19 @@ def get_sites(
         State filter. Accepts a full name (``"Wisconsin"``), a two-letter
         postal code (``"WI"``), or a two-digit ANSI/FIPS code (``"55"``).
         The 50 states, DC, and the five US territories.
+    county : str, int, or iterable of them, optional
+        County filter (the recommended parameter). Accepts a five-digit FIPS
+        code (``"55025"`` or ``55025``), the ``"US:55:025"`` form, or, with
+        ``state``, a name (``"Dane County"`` or ``"Dane"``) or three-digit
+        county code (``"025"``). A dataretrieval argument rather than an API
+        field: it is sent as the API's ``state_name`` and ``county_name``, and
+        ``state``, if given, names the one state the counties are in rather
+        than filtering separately. One state per call. Connecticut raises
+        ``ValueError``: NGWMN still files its sites under the counties replaced
+        in 2022, so pass ``county_name`` instead. See
+        ``dataretrieval.codes.to_county``.
     county_name : str or iterable of str, optional
-        County name filter.
+        County name filter, as NGWMN spells it (``"Dane County"``).
     aquifer_name, site_type, aquifer_type_code : str or iterable, optional
         Aquifer name, site type, and aquifer-type code.
     qw_sys_name, qw_sn_flag, qw_baseline_flag : str or iterable, optional
diff --git a/dataretrieval/nwdc.py b/dataretrieval/nwdc.py
index a42b8254..8ee87295 100644
--- a/dataretrieval/nwdc.py
+++ b/dataretrieval/nwdc.py
@@ -49,6 +49,7 @@
 from dataretrieval._querying import _raise_for_status, to_str
 from dataretrieval._response_metadata import BaseMetadata
 from dataretrieval._validation import render_options, require_exactly_one
+from dataretrieval.codes.counties import to_county
 from dataretrieval.codes.states import to_state
 from dataretrieval.configuration import (
     BaseConfiguration,
@@ -104,7 +105,7 @@ def get_wateruse(
     model: str,
     variable: str | Iterable[str] | None = None,
     state: str | int | Iterable[str | int] | None = None,
-    county: str | Iterable[str] | None = None,
+    county: str | int | Iterable[str | int] | None = None,
     huc: str | Iterable[str] | None = None,
     time_resolution: str | None = None,
     start_date: str | None = None,
@@ -153,9 +154,14 @@ def get_wateruse(
         One or more US states/territories to query. Each accepts a full name
         (``"Wisconsin"``), a two-letter postal code (``"WI"``), or a two-digit ANSI/FIPS
         code (``"55"`` or ``55``), matching :func:`dataretrieval.ngwmn.get_sites`.
-    county : string or iterable, optional
-        One or more five-digit county FIPS codes — state FIPS + county FIPS,
-        e.g. ``"55025"`` for Dane County, Wisconsin.
+    county : string, int, or iterable, optional
+        One or more counties. Each accepts a five-digit FIPS code — state FIPS +
+        county FIPS, e.g. ``"55025"`` or ``55025`` for Dane County, Wisconsin —
+        the ``"US:55:025"`` form, or, with ``state``, a name (``"Dane County"``
+        or ``"Dane"``) or three-digit county code (``"025"``). With ``county``,
+        ``state`` names the one state the counties are in rather than a second
+        area. Sent as the API's ``countyCd:<FIPS>`` location. See
+        ``dataretrieval.codes.to_county``.
     huc : string or iterable, optional
         One or more hydrologic unit codes. Each code's level is taken from its
         length: a 2-digit code queries a HUC2 region, 8-digit a HUC8 subbasin,
@@ -163,7 +169,8 @@ def get_wateruse(
         ``"07070005"``, ``"010900020502"``).
 
         Provide exactly one of ``state``, ``county``, or ``huc`` (each may be a
-        single value or a list).
+        single value or a list); ``state`` may accompany ``county`` to qualify
+        it.
     time_resolution : string, optional
         Temporal resolution: ``"monthly"``, ``"annualcy"`` (annual, calendar
         year), or ``"annualwy"`` (annual, water year). See
@@ -199,8 +206,8 @@ def get_wateruse(
     ------
     ValueError
         If not exactly one of ``state``, ``county``, or ``huc`` is given, or a
-        given selector is malformed (an unrecognized state, a county code that
-        is not five digits, or a HUC of invalid length).
+        given selector is malformed (an unrecognized state or county, or a HUC
+        of invalid length).
     DataRetrievalError
         On an HTTP error response, the typed subclass for the status (see
         :func:`dataretrieval.exceptions.error_for_status`). A transient 429,
@@ -273,24 +280,27 @@ def get_wateruse(
 # per location (see :func:`_fan_out`).
 _LOCATION_BUILDERS: dict[str, Callable[[Any], list[str]]] = {
     "state": lambda v: [f"stateCd:{c}" for c in _as_list(to_state(v, to="postal"))],
-    "county": lambda v: [f"countyCd:{_validate_county(c)}" for c in _as_list(v)],
+    "county": lambda v: [f"countyCd:{c}" for c in _as_list(v)],
     "huc": lambda v: [f"huc{len(c)}:{c}" for c in map(_validate_huc, _as_list(v))],
 }
 
 
 def _resolve_locations(
     state: str | int | Iterable[str | int] | None,
-    county: str | Iterable[str] | None,
+    county: str | int | Iterable[str | int] | None,
     huc: str | Iterable[str] | None,
 ) -> list[str]:
     """Build the NWDC ``location=<type>:<id>`` value(s) from the selectors.
 
     Exactly one of ``state`` / ``county`` / ``huc`` must be given; each may be a
     single value or a list. ``state`` is normalized to the two-letter postal
-    code ``stateCd`` requires; ``county`` is a five-digit FIPS code; and a
+    code ``stateCd`` requires; ``county`` to a five-digit FIPS code, with
+    ``state`` qualifying it rather than counting as a second location; and a
     ``huc`` code's length selects its level (``huc2`` … ``huc12``). Returns one
     location string per value — the caller issues one request per location.
     """
+    if county is not None:
+        county, state = to_county(county, "fips", state=state), None
     selectors = {"state": state, "county": county, "huc": huc}
     name, value = require_exactly_one(selectors, context="as the query's location")
     locations = _LOCATION_BUILDERS[name](value)
@@ -313,17 +323,6 @@ def _as_list(value: object) -> list[Any]:
     return [value]
 
 
-def _validate_county(value: object) -> str:
-    """Validate and normalize a five-digit state+county FIPS code."""
-    code = str(value).strip()
-    if not (code.isdigit() and len(code) == 5):
-        raise ValueError(
-            "county must be a five-digit state+county FIPS code "
-            f"(e.g. '55025'), got {value!r}."
-        )
-    return code
-
-
 def _validate_huc(value: object) -> str:
     """Validate a HUC code (even length 2-12 digits; level set by length)."""
     code = str(value).strip()
diff --git a/dataretrieval/waterdata/metadata.py b/dataretrieval/waterdata/metadata.py
index eb26d98e..5acdb93c 100644
--- a/dataretrieval/waterdata/metadata.py
+++ b/dataretrieval/waterdata/metadata.py
@@ -15,6 +15,7 @@
 
 from dataretrieval.waterdata.utils import (
     _get_args,
+    _with_location_county,
     _with_state,
     get_ogc_data,
 )
@@ -36,6 +37,7 @@ def get_monitoring_locations(
     state: str | Iterable[str] | None = None,
     state_code: str | Iterable[str] | None = None,
     state_name: str | Iterable[str] | None = None,
+    county: str | int | Iterable[str | int] | None = None,
     county_code: str | Iterable[str] | None = None,
     county_name: str | Iterable[str] | None = None,
     minor_civil_division_code: str | Iterable[str] | None = None,
@@ -133,6 +135,17 @@ def get_monitoring_locations(
     state_name : string or iterable of strings, optional
         The name of the state or state equivalent in which the monitoring location
         is located.
+    county : string, integer, or iterable of them, optional
+        County filter (the recommended parameter). Accepts a five-digit FIPS
+        code (``"55025"`` or ``55025``), the ``"US:55:025"`` form, or, with
+        ``state``, a name (``"Dane County"`` or
+        ``"Dane"``) or three-digit county code (``"025"``). A dataretrieval
+        argument rather than an API field: it is sent as the API's
+        ``state_code`` and ``county_code``, and ``state``, if given, names the
+        one state the counties are in rather than filtering separately.
+        Counties in more than one state are sent as a CQL ``filter``, so they
+        cannot be combined with ``filter``. See
+        ``dataretrieval.codes.to_county``.
     county_code : string or iterable of strings, optional
         The code for the county or county equivalent (parish, borough, etc.) in which
         the monitoring location is located. A `list of codes
@@ -337,7 +350,8 @@ def get_monitoring_locations(
     # Build argument dictionary, omitting None values (resolving the unified
     # `state` argument into the OGC `state_name` queryable).
     args = _get_args(
-        _with_state(locals(), to="name", into="state_name"), exclude={"max_rows"}
+        _with_state(_with_location_county(locals()), to="name", into="state_name"),
+        exclude={"max_rows"},
     )
 
     return get_ogc_data(args, collection, max_rows=max_rows)
@@ -621,6 +635,7 @@ def get_combined_metadata(
     state: str | Iterable[str] | None = None,
     state_code: str | Iterable[str] | None = None,
     state_name: str | Iterable[str] | None = None,
+    county: str | int | Iterable[str | int] | None = None,
     county_code: str | Iterable[str] | None = None,
     county_name: str | Iterable[str] | None = None,
     minor_civil_division_code: str | Iterable[str] | None = None,
@@ -733,6 +748,17 @@ def get_combined_metadata(
         State/territory filter (the recommended parameter). Accepts a full
         name (``"Wisconsin"``), a two-letter postal code (``"WI"``), or a
         two-digit ANSI/FIPS code (``"55"``).
+    county : string, integer, or iterable of them, optional
+        County filter (the recommended parameter). Accepts a five-digit FIPS
+        code (``"55025"`` or ``55025``), the ``"US:55:025"`` form, or, with
+        ``state``, a name (``"Dane County"`` or
+        ``"Dane"``) or three-digit county code (``"025"``). A dataretrieval
+        argument rather than an API field: it is sent as the API's
+        ``state_code`` and ``county_code``, and ``state``, if given, names the
+        one state the counties are in rather than filtering separately.
+        Counties in more than one state are sent as a CQL ``filter``, so they
+        cannot be combined with ``filter``. See
+        ``dataretrieval.codes.to_county``.
     state_name, county_name, hydrologic_unit_code, site_type, \
 site_type_code : string or iterable of strings, optional
         Common location-catalog filters shared with the
@@ -846,7 +872,8 @@ def get_combined_metadata(
 
     # Resolve the unified `state` argument into the OGC `state_name` queryable.
     args = _get_args(
-        _with_state(locals(), to="name", into="state_name"), exclude={"max_rows"}
+        _with_state(_with_location_county(locals()), to="name", into="state_name"),
+        exclude={"max_rows"},
     )
 
     return get_ogc_data(args, collection, max_rows=max_rows)
diff --git a/dataretrieval/waterdata/time_series.py b/dataretrieval/waterdata/time_series.py
index c83232f0..6c8d685d 100644
--- a/dataretrieval/waterdata/time_series.py
+++ b/dataretrieval/waterdata/time_series.py
@@ -20,6 +20,7 @@
 from dataretrieval.waterdata.utils import (
     _get_args,
     _with_state,
+    _with_statistics_county,
     get_ogc_data,
 )
 
@@ -884,6 +885,7 @@ def get_stats_por(
     country_code: str | Iterable[str] | None = None,
     state: str | Iterable[str] | None = None,
     state_code: str | Iterable[str] | None = None,
+    county: str | int | Iterable[str | int] | None = None,
     county_code: str | Iterable[str] | None = None,
     start_date: str | None = None,
     end_date: str | None = None,
@@ -925,6 +927,14 @@ def get_stats_por(
     state_code: string, optional
         State query parameter. Takes the format "US:XX", where XX is
         the two-digit state code. API defaults to "US:42" (Pennsylvania).
+    county: string, integer, or iterable of them, optional
+        County filter (the recommended parameter). Accepts a five-digit FIPS
+        code ("55025" or 55025), the "US:55:025" form, or, with ``state``, a
+        name ("Dane County" or "Dane") or three-digit county code ("025"). A
+        dataretrieval argument rather than an API field: it is sent as the
+        API's ``county_code``, in its "US:XX:YYY" format, and ``state``, if
+        given, names the one state the counties are in rather than filtering
+        separately. See ``dataretrieval.codes.to_county``.
     county_code: string, optional
         County query parameter. Takes the format "US:XX:YYY", where XX is
         the two-digit state code and YYY is the three-digit county code.
@@ -1009,7 +1019,7 @@ def get_stats_por(
     """
     # Build argument dictionary, omitting None values
     params = _get_args(
-        _with_state(locals(), to="fips_us", into="state_code"),
+        _with_state(_with_statistics_county(locals()), to="fips_us", into="state_code"),
         exclude={"expand_percentiles"},
     )
 
@@ -1024,6 +1034,7 @@ def get_stats_date_range(
     country_code: str | Iterable[str] | None = None,
     state: str | Iterable[str] | None = None,
     state_code: str | Iterable[str] | None = None,
+    county: str | int | Iterable[str | int] | None = None,
     county_code: str | Iterable[str] | None = None,
     start_date: str | None = None,
     end_date: str | None = None,
@@ -1065,6 +1076,14 @@ def get_stats_date_range(
     state_code: string, optional
         State query parameter. Takes the format "US:XX", where XX is
         the two-digit state code. API defaults to "US:42" (Pennsylvania).
+    county: string, integer, or iterable of them, optional
+        County filter (the recommended parameter). Accepts a five-digit FIPS
+        code ("55025" or 55025), the "US:55:025" form, or, with ``state``, a
+        name ("Dane County" or "Dane") or three-digit county code ("025"). A
+        dataretrieval argument rather than an API field: it is sent as the
+        API's ``county_code``, in its "US:XX:YYY" format, and ``state``, if
+        given, names the one state the counties are in rather than filtering
+        separately. See ``dataretrieval.codes.to_county``.
     county_code: string, optional
         County query parameter. Takes the format "US:XX:YYY", where XX is
         the two-digit state code and YYY is the three-digit county code.
@@ -1155,7 +1174,7 @@ def get_stats_date_range(
     """
     # Build argument dictionary, omitting None values
     params = _get_args(
-        _with_state(locals(), to="fips_us", into="state_code"),
+        _with_state(_with_statistics_county(locals()), to="fips_us", into="state_code"),
         exclude={"expand_percentiles"},
     )
 
diff --git a/dataretrieval/waterdata/utils.py b/dataretrieval/waterdata/utils.py
index ede2e117..49df745d 100644
--- a/dataretrieval/waterdata/utils.py
+++ b/dataretrieval/waterdata/utils.py
@@ -22,6 +22,8 @@
 import pandas as pd
 
 from dataretrieval._deprecation import warn_deprecated
+from dataretrieval._validation import reject_together
+from dataretrieval.codes.counties import apply_county
 from dataretrieval.codes.states import apply_state
 from dataretrieval.credentials import refuse_credential_keywords
 from dataretrieval.ogc import OgcDialect, prepare_request_args
@@ -189,6 +191,56 @@ def _with_state(local_vars: dict[str, Any], *, to: str, into: str) -> dict[str,
     )
 
 
+def _with_location_county(local_vars: dict[str, Any]) -> dict[str, Any]:
+    """Resolve the unified ``county`` argument for the location collections.
+
+    ``monitoring-locations`` and ``combined-metadata`` file a county under two
+    fields, ``state_code`` and a three-digit ``county_code`` that repeats
+    across states, so counties are sent as (state, county) pairs. Counties in
+    one state go out as ``state_code`` plus a ``county_code`` list; counties in
+    several need a CQL ``filter`` OR-ing the pairs, which the request planner
+    splits at its top-level ``OR`` when it outgrows the request size cap.
+    """
+    _flatten_queryables(local_vars)
+    user_filter = local_vars.get("filter")
+    return apply_county(
+        local_vars,
+        render=lambda fips: _location_county_params(fips, user_filter),
+        reject=("state_code", "state_name", "county_code", "county_name"),
+    )
+
+
+def _location_county_params(fips: list[str], user_filter: object) -> dict[str, Any]:
+    """The location collections' parameters for counties ``fips``."""
+    states = {f[:2] for f in fips}
+    if len(states) == 1:
+        return {"state_code": states.pop(), "county_code": [f[2:] for f in fips]}
+    reject_together(
+        {"county": fips, "filter": user_filter},
+        context="when the counties are in more than one state, which is sent "
+        "as a filter",
+        remedy="Pass the counties of one state per call, or write the counties "
+        "into filter yourself, e.g. \"(state_code='55' AND county_code='025') OR "
+        "(state_code='17' AND county_code='031')\".",
+    )
+    return {
+        "filter": " OR ".join(
+            f"(state_code='{f[:2]}' AND county_code='{f[2:]}')" for f in fips
+        )
+    }
+
+
+def _with_statistics_county(local_vars: dict[str, Any]) -> dict[str, Any]:
+    """Resolve the unified ``county`` argument for the statistics service,
+    which takes each county as one ``county_code`` of the form ``US:55:025``."""
+    _flatten_queryables(local_vars)
+    return apply_county(
+        local_vars,
+        render=lambda fips: {"county_code": [f"US:{f[:2]}:{f[2:]}" for f in fips]},
+        reject=("state_code", "county_code"),
+    )
+
+
 def get_ogc_data(
     args: dict[str, Any],
     collection: str,
diff --git a/docs/source/architecture/decisions/0013-core-and-domain-terms.rst b/docs/source/architecture/decisions/0013-core-and-domain-terms.rst
index 105b35d2..36535c61 100644
--- a/docs/source/architecture/decisions/0013-core-and-domain-terms.rst
+++ b/docs/source/architecture/decisions/0013-core-and-domain-terms.rst
@@ -6,6 +6,9 @@ Status
 
 Accepted
 
+Amended after acceptance under :doc:`0000-documenting-decisions`; the
+``Notes`` section records the clause added.
+
 Context
 -------
 
@@ -68,7 +71,7 @@ The glossary holds two kinds of term, and they impose different obligations.
 
 **Core terms are ours.** The package invented them and no service defines
 them: everything under *Retrieval*, *Failure and resumption*, *Configuration*
-and *Boundaries*, plus *Collection family* and *Metadata*. One spelling,
+and *Boundaries*, plus *Collection family*, *Metadata* and *Unified argument*. One spelling,
 enforced everywhere it appears -- prose, identifiers, tests. A second spelling
 of a core term is a defect, not a variation, and is fixed rather than recorded.
 This is what makes the lower-level modules shareable: transport, configuration
@@ -99,6 +102,30 @@ Two rules follow:
   surface is not a legacy name; it is that adapter using its service's
   terms, and belongs with the term's own entry.
 
+**A unified argument may stand beside a service's spelling.** Where one domain
+concept is a filter in several adapters and each spells it differently, a getter
+may also take an argument the package names -- ``state``, ``county`` -- that
+accepts every common spelling of the concept and sends the service its own.
+It is added to the adapter's surface and removes nothing from it, so a caller
+who has read a service's documentation still finds the parameters described
+there. It is allowed on four conditions:
+
+- **The service's parameters stay.** They are not deprecated, and they still
+  send the service's raw value, including values the conversion does not cover
+  (a non-US FIPS code, a county the service files under a retired name).
+- **The conversion is exact.** It is a table in ``dataretrieval.codes``, checked
+  against the service's own reference collection by a live test. A value the
+  table does not hold raises ``ValueError`` naming the native parameters,
+  rather than being guessed at or sent unchecked. A service that cannot express
+  a converted value exactly raises too: NGWMN still files Connecticut sites
+  under the counties the state replaced with planning regions, so
+  ``ngwmn.get_sites(county="09110")`` raises rather than returning no rows.
+- **It cannot be combined with what it replaces.** Passing it together with the
+  native parameter it is sent as raises ``ValueError``.
+- **Its docstring names what it is sent as.** It says the argument is
+  dataretrieval's rather than the API's, and names the field or fields the
+  service receives, so the two documentations can be read against each other.
+
 Consequences
 ------------
 
@@ -114,6 +141,10 @@ Consequences
   its definition rather than a list of exceptions.
 - A glossary entry now has an obligation to say which kind it is. That is a
   small cost per term and the reason the distinction is usable at all.
+- A caller filtering by place across adapters learns one spelling rather than
+  one per service, at the cost of a table per concept to keep current. The
+  live tests that compare each table with its reference collection are what
+  keep that cost visible.
 - The package's own inconsistencies in core vocabulary become defects to fix
   rather than variations to tolerate. The resolution chain's
   ``tier``-for-*source* identifiers are the current example.
@@ -135,6 +166,12 @@ reader notices immediately.
 Whether a given adapter docstring should say *site* or *monitoring location*
 remains a review judgement, and is meant to.
 
+For unified arguments, ``tests/utils_test.py`` and ``tests/counties_test.py``
+compare the state and county tables with the Water Data ``states`` and
+``counties`` collections, and ``tests/ngwmn_test.py`` checks that NGWMN files
+its sites under the table's county names, live. Each getter's tests assert the
+mutual exclusion with its native parameters.
+
 Notes
 -----
 
@@ -145,3 +182,10 @@ made the gap visible rather than creating it.
 
 The per-service spellings in the table above were read from the adapters on
 2026-09-01.
+
+The unified-argument clause was added on 2026-10-01, with ``county``. ``state``
+had been a unified argument since NGWMN joined the shared OGC code, with no
+record saying why it did not contradict the rule that each adapter keeps its
+service's spelling, and review read it as hiding the APIs' own parameters. The
+clause states the conditions both arguments already met, so the next one is
+judged against them rather than against that precedent.
diff --git a/tests/counties_test.py b/tests/counties_test.py
new file mode 100644
index 00000000..3d0f6885
--- /dev/null
+++ b/tests/counties_test.py
@@ -0,0 +1,161 @@
+"""``codes.counties``: the county table and the ``county`` argument's conversion.
+
+The getters that take ``county`` are tested in their adapter's file; this one
+covers what they share -- which identifiers resolve, to what, and which raise.
+"""
+
+import pytest
+
+from dataretrieval.codes.counties import apply_county, counties, to_county
+
+
+@pytest.mark.parametrize(
+    ("value", "state"),
+    [
+        ("55025", None),
+        (55025, None),
+        (" 55025 ", None),
+        ("US:55:025", None),
+        ("us:55:025", None),
+        ("025", "WI"),
+        ("Dane County", "WI"),
+        ("dane county", "Wisconsin"),
+        ("Dane", "55"),
+        ("DANE", "US:55"),
+        ("55025", "WI"),
+    ],
+)
+def test_every_form_resolves_to_the_same_county(value, state):
+    assert to_county(value, state=state) == "55025"
+    assert to_county(value, "fips_us", state=state) == "US:55:025"
+    assert to_county(value, "name", state=state) == "Dane County"
+
+
+def test_an_integer_keeps_its_leading_zero():
+    """Autauga County, Alabama is 01001; as an integer it is 1001."""
+    assert to_county(1001) == "01001"
+    assert to_county("1001") == "01001"
+
+
+@pytest.mark.parametrize(
+    ("value", "state", "name"),
+    [
+        ("Orleans", "LA", "Orleans Parish"),
+        ("Juneau", "AK", "Juneau City and Borough"),
+        ("Bethel", "AK", "Bethel Census Area"),
+        ("Anchorage", "AK", "Anchorage Municipality"),
+        ("Adjuntas", "PR", "Adjuntas Municipio"),
+        ("Capitol", "CT", "Capitol Planning Region"),
+        ("St. Croix", "VI", "St. Croix Island"),
+        ("St Louis County", "MO", "St. Louis County"),
+        ("District of Columbia", "DC", "District of Columbia"),
+        ("Charles City", "VA", "Charles City County"),
+    ],
+)
+def test_a_county_equivalent_matches_without_its_designation(value, state, name):
+    """Parishes, boroughs, municipios, and planning regions resolve like
+    counties; periods are optional, as in "St Louis"."""
+    assert to_county(value, "name", state=state) == name
+
+
+def test_a_list_resolves_element_wise():
+    assert to_county(["55025", "US:17:031", 1001]) == ["55025", "17031", "01001"]
+    assert to_county(("Dane", "Iowa"), "name", state="WI") == [
+        "Dane County",
+        "Iowa County",
+    ]
+
+
+@pytest.mark.parametrize(
+    ("value", "state", "match"),
+    [
+        ("Dane", None, r"names repeat across states\. Pass the state too"),
+        ("025", None, "not a recognized US county"),
+        ("99999", None, "not a recognized US county"),
+        (True, None, "not a recognized US county"),
+        ("55025", "IL", "is in Wisconsin, not Illinois"),
+        ("Fairfax", "VA", "'Fairfax County', 'Fairfax City'. Pass the full name"),
+        ("Baltimore", "MD", "more than one county in Maryland"),
+        ("Dain", "WI", "Did you mean 'Dane County'"),
+        ("Dane", ["WI", "IL"], "must be a single state"),
+        ("Dane", "Atlantis", "not a recognized US state"),
+    ],
+)
+def test_an_unresolvable_county_raises_with_a_remedy(value, state, match):
+    with pytest.raises(ValueError, match=match):
+        to_county(value, state=state)
+
+
+def test_a_retired_connecticut_county_points_to_the_planning_regions():
+    """Connecticut replaced its counties with planning regions in 2022; the
+    Water Data services accept only the new codes."""
+    with pytest.raises(ValueError, match="planning regions, codes 09110 to 09190"):
+        to_county("09003")
+
+
+def test_to_rejects_an_unknown_representation():
+    with pytest.raises(ValueError, match="to"):
+        to_county("55025", "postal")
+
+
+def test_the_table_covers_the_states_and_territories_and_only_them():
+    from dataretrieval.codes.states import fips_codes
+
+    assert {f[:2] for f in counties} == set(fips_codes.values())
+    assert all(len(f) == 5 and f.isdigit() for f in counties)
+    assert not [f for f in counties if f.endswith("000")]
+
+
+class TestApplyCounty:
+    @staticmethod
+    def _render(fips):
+        return {"county_code": fips}
+
+    def test_absent_is_a_no_op_and_leaves_state_alone(self):
+        args = {"state": "WI"}
+        assert apply_county(args, render=self._render, reject=()) == {"state": "WI"}
+
+    def test_state_qualifies_the_counties_and_is_consumed(self):
+        args = {"county": "Dane", "state": "WI", "limit": 5}
+        assert apply_county(args, render=self._render, reject=()) == {
+            "county_code": ["55025"],
+            "limit": 5,
+        }
+
+    def test_a_native_parameter_cannot_be_combined_with_county(self):
+        with pytest.raises(ValueError, match="county and county_code cannot be"):
+            apply_county(
+                {"county": "55025", "county_code": "025"},
+                render=self._render,
+                reject=("county_code",),
+            )
+
+    def test_an_unrecognized_county_names_the_native_parameters(self):
+        with pytest.raises(ValueError, match="Or pass state_code or county_code"):
+            apply_county(
+                {"county": "99999"},
+                render=self._render,
+                reject=("state_code", "county_code"),
+            )
+
+
+@pytest.mark.live
+def test_the_table_matches_the_water_data_counties_collection():
+    """Each code and name is the one the services filter on.
+
+    The table is a snapshot of this collection. A failure means the Census
+    Bureau or the service changed a county; regenerate the table from the
+    collection (``country_code=US``, without ``000`` and the states
+    ``codes.states`` does not cover).
+    """
+    from dataretrieval.codes.states import fips_codes
+    from dataretrieval.waterdata import get_reference_table
+
+    df, _ = get_reference_table("counties")
+    covered = set(fips_codes.values())
+    live = {
+        row.state_fips_code + row.county_fips_code: row.county_name
+        for row in df[df["country_code"] == "US"].itertuples()
+        if row.state_fips_code in covered and row.county_fips_code != "000"
+    }
+    assert live == counties
diff --git a/tests/ngwmn_test.py b/tests/ngwmn_test.py
index d73ae0f2..26c4438a 100644
--- a/tests/ngwmn_test.py
+++ b/tests/ngwmn_test.py
@@ -11,6 +11,7 @@
 cannot tell us, because the mock is what would need updating.
 """
 
+import json
 import re
 from urllib.parse import parse_qs, urlsplit
 
@@ -348,6 +349,50 @@ def test_get_sites_state_accepts_name_postal_or_fips(httpx_mock):
         assert "state" not in qs
 
 
+def test_get_sites_county_sends_state_name_and_county_name(httpx_mock):
+    """``sites`` files a county by name; ``state`` qualifies it."""
+    _mock(httpx_mock, "sites", _SITES)
+
+    ngwmn.get_sites(county="Dane", state="WI", skip_geometry=True)
+    ngwmn.get_sites(county="02020", skip_geometry=True)
+
+    dane, anchorage = _queries(httpx_mock, "sites")
+    assert dane["state_name"] == ["Wisconsin"]
+    assert dane["county_name"] == ["Dane County"]
+    # NGWMN names Anchorage the other way round from the county table.
+    assert anchorage["county_name"] == ["Municipality of Anchorage"]
+    assert "county" not in dane and "state" not in dane
+
+
+def test_get_sites_posts_a_county_name_list(httpx_mock):
+    """A comma-joined ``county_name`` matches nothing on NGWMN, where the
+    same names POSTed as CQL2 match; this applies to ``county_name`` too."""
+    httpx_mock.add_response(method="POST", url=_items_re("sites"), json=_SITES)
+
+    ngwmn.get_sites(county=["55025", "55065"], skip_geometry=True)
+    ngwmn.get_sites(county_name=["Dane County", "Lafayette County"], skip_geometry=True)
+
+    for req in httpx_mock.get_requests():
+        assert req.method == "POST"
+        (clause,) = json.loads(req.content)["args"]
+        assert clause["args"][1] == ["Dane County", "Lafayette County"]
+    first = parse_qs(urlsplit(str(httpx_mock.get_requests()[0].url)).query)
+    assert first["state_name"] == ["Wisconsin"]
+
+
+@pytest.mark.parametrize(
+    ("kwargs", "match"),
+    [
+        ({"county": ["55025", "17031"]}, "counties from one state per call"),
+        ({"county": "09110"}, "Pass county_name directly"),
+        ({"county": "55025", "county_name": "Dane County"}, "cannot be combined"),
+    ],
+)
+def test_get_sites_county_refusals(kwargs, match):
+    with pytest.raises(ValueError, match=match):
+        ngwmn.get_sites(**kwargs)
+
+
 # --- providers ---------------------------------------------------------------
 
 
@@ -600,6 +645,32 @@ def test_a_configured_base_url_redirects_ngwmn_alone(httpx_mock):
 # --- live upstream monitor ---------------------------------------------------
 
 
+@pytest.mark.live
+def test_county_names_still_match_the_table_upstream():
+    """Every county NGWMN files a site under is the table's name for it, but for
+    ``ngwmn._NGWMN_COUNTY_NAMES`` and the retired Connecticut counties.
+
+    If this fails, NGWMN renamed a county (add it to ``_NGWMN_COUNTY_NAMES``),
+    or moved Connecticut to planning regions (drop ``_LEGACY_COUNTY_STATES``).
+    """
+    from dataretrieval.codes.counties import counties
+    from dataretrieval.codes.states import to_state
+    from dataretrieval.ngwmn import _LEGACY_COUNTY_STATES, _NGWMN_COUNTY_NAMES
+
+    df, _ = ngwmn.get_sites(
+        properties=["state_name", "county_name"], skip_geometry=True
+    )
+    known = {
+        (to_state(f[:2], "name"), _NGWMN_COUNTY_NAMES.get(f, name))
+        for f, name in counties.items()
+        if f[:2] not in _LEGACY_COUNTY_STATES
+    }
+    legacy = {to_state(s, "name") for s in _LEGACY_COUNTY_STATES}
+    filed = set(zip(df["state_name"], df["county_name"], strict=True))
+    assert {p for p in filed if p[0] not in legacy} <= known
+    assert all(not name.endswith("Planning Region") for s, name in filed if s in legacy)
+
+
 @pytest.mark.live
 def test_state_queryables_still_diverge_upstream():
     """The NGWMN ``sites`` and ``providers`` collections expose different state
diff --git a/tests/nwdc_test.py b/tests/nwdc_test.py
index d41fbb90..269af76c 100644
--- a/tests/nwdc_test.py
+++ b/tests/nwdc_test.py
@@ -402,6 +402,12 @@ def test_resolve_locations_requires_exactly_one():
     with pytest.raises(ValueError, match="exactly one"):
         _resolve_locations(None, None, None)
     with pytest.raises(ValueError, match="exactly one"):
+        _resolve_locations(None, "55025", "04")
+
+
+def test_state_qualifies_county_rather_than_naming_a_second_location():
+    assert _resolve_locations("WI", "Dane", None) == ["countyCd:55025"]
+    with pytest.raises(ValueError, match="in Wisconsin, not Rhode Island"):
         _resolve_locations("RI", "55025", None)
 
 
diff --git a/tests/utils_test.py b/tests/utils_test.py
index c2fcb6c2..ef9a93e2 100644
--- a/tests/utils_test.py
+++ b/tests/utils_test.py
@@ -526,24 +526,31 @@ class TestTerritories:
     """
 
     @pytest.mark.parametrize(
-        ("value", "name", "postal", "fips"),
+        ("name", "postal", "fips"),
         [
-            ("Puerto Rico", "Puerto Rico", "PR", "72"),
-            ("PR", "Puerto Rico", "PR", "72"),
-            ("72", "Puerto Rico", "PR", "72"),
-            ("US:72", "Puerto Rico", "PR", "72"),
-            ("Guam", "Guam", "GU", "66"),
-            ("VI", "US Virgin Islands", "VI", "78"),
-            ("60", "American Samoa", "AS", "60"),
-            ("MP", "Northern Mariana Islands", "MP", "69"),
+            ("Puerto Rico", "PR", "72"),
+            ("Guam", "GU", "66"),
+            ("Virgin Islands", "VI", "78"),
+            ("American Samoa", "AS", "60"),
+            ("Northern Mariana Islands", "MP", "69"),
         ],
     )
-    def test_every_encoding_resolves(self, value, name, postal, fips):
+    def test_each_territory_is_in_both_code_tables(self, name, postal, fips):
+        """Each code resolves to the others. The input encodings themselves are
+        :class:`Test_to_state`'s concern."""
         from dataretrieval.codes.states import to_state
 
-        assert to_state(value, "name") == name
-        assert to_state(value, "postal") == postal
-        assert to_state(value, "fips") == fips
+        for value in (name, postal, fips):
+            assert to_state(value, "name") == name
+            assert to_state(value, "postal") == postal
+            assert to_state(value, "fips") == fips
+
+    def test_the_census_name_of_the_virgin_islands_is_accepted(self):
+        """The table names it as the services do; the name it had before is
+        still accepted as input."""
+        from dataretrieval.codes.states import to_state
+
+        assert to_state("US Virgin Islands") == "Virgin Islands"
 
     def test_the_ngwmn_shim_routes_a_territory_to_each_queryable(self):
         """``sites`` filters on ``state_name``, ``providers`` on ``state``."""
@@ -557,6 +564,26 @@ def test_the_ngwmn_shim_routes_a_territory_to_each_queryable(self):
         }
 
 
+@pytest.mark.live
+def test_state_names_match_the_water_data_states_collection():
+    """Each name is the one the services filter ``state_name`` on (ADR 0013).
+
+    Water Data and NGWMN match ``state_name`` exactly, so a name that differs
+    from theirs returns no rows rather than an error.
+    """
+    from dataretrieval.codes.states import fips_codes, state_codes
+    from dataretrieval.waterdata import get_reference_table
+
+    df, _ = get_reference_table("states")
+    expected = {fips: (name, state_codes[name]) for name, fips in fips_codes.items()}
+    live = {
+        row.state_fips_code: (row.state_name, row.state_postal_code.lower())
+        for row in df[df["country_code"] == "US"].itertuples()
+        if row.state_fips_code in expected
+    }
+    assert live == expected
+
+
 class TestApplyStateUnrecognized:
     """The remedy for an unknown value names the endpoint's API state parameter.
 
diff --git a/tests/waterdata_test.py b/tests/waterdata_test.py
index dbde43cf..d5051192 100644
--- a/tests/waterdata_test.py
+++ b/tests/waterdata_test.py
@@ -976,6 +976,72 @@ def test_get_monitoring_locations(httpx_mock):
     assert hasattr(md, "url") and hasattr(md, "query_time")
 
 
+def test_county_is_sent_as_state_code_and_county_code_pairs(httpx_mock):
+    """A county code repeats across states, so ``county`` sends the pair; with
+    ``state``, the state qualifies the county rather than filtering again."""
+    _mock_items(httpx_mock, "monitoring-locations")
+    _mock_items(httpx_mock, "combined-metadata")
+
+    get_monitoring_locations(county="Dane", state="WI")
+    get_combined_metadata(county=55025)
+
+    for qs in _sent(httpx_mock):
+        assert qs["state_code"] == ["55"]
+        assert qs["county_code"] == ["025"]
+        assert "state_name" not in qs and "state" not in qs and "county" not in qs
+
+
+def test_counties_in_one_state_post_a_county_code_list(httpx_mock):
+    _mock_items(httpx_mock, "monitoring-locations")
+
+    get_monitoring_locations(county=["55025", "US:55:021"])
+
+    (req,) = httpx_mock.get_requests()
+    assert req.method == "POST"
+    assert parse_qs(urlsplit(str(req.url)).query)["state_code"] == ["55"]
+    assert json.loads(req.content)["args"] == [
+        {"op": "in", "args": [{"property": "county_code"}, ["025", "021"]]}
+    ]
+
+
+def test_counties_in_several_states_or_their_pairs_in_a_filter(httpx_mock):
+    """Separate state_code and county_code lists would also match Cook
+    County's code (031) in Wisconsin; the pairs must be OR-ed."""
+    _mock_items(httpx_mock, "monitoring-locations")
+
+    get_monitoring_locations(county=["55025", "17031"])
+
+    (qs,) = _sent(httpx_mock)
+    assert qs["filter"] == [
+        "(state_code='55' AND county_code='025') OR "
+        "(state_code='17' AND county_code='031')"
+    ]
+    assert "state_code" not in qs and "county_code" not in qs
+
+
+def test_counties_in_several_states_cannot_join_a_caller_filter():
+    with pytest.raises(ValueError, match="county and filter cannot be combined"):
+        get_monitoring_locations(
+            county=["55025", "17031"], filter="site_type_code='ST'"
+        )
+
+
+def test_county_in_one_state_keeps_a_caller_filter(httpx_mock):
+    _mock_items(httpx_mock, "monitoring-locations")
+
+    get_monitoring_locations(county="55025", filter="site_type_code='ST'")
+
+    (qs,) = _sent(httpx_mock)
+    assert qs["filter"] == ["site_type_code='ST'"]
+    assert qs["county_code"] == ["025"]
+
+
+@pytest.mark.parametrize("native", ["state_code", "state_name", "county_code"])
+def test_county_cannot_be_combined_with_a_native_location_parameter(native):
+    with pytest.raises(ValueError, match=f"county and {native} cannot be combined"):
+        get_monitoring_locations(county="55025", **{native: "x"})
+
+
 def test_get_monitoring_locations_hucs_uses_post_cql(httpx_mock):
     """``monitoring-locations`` is a POST/CQL2 collection in the Water Data
     dialect, so a multi-value filter goes out as a CQL2 body rather than a
@@ -1452,6 +1518,24 @@ def test_get_stats_por(httpx_mock):
     assert df.loc[df["computation"] == "arithmetic_mean", "percentile"].isna().all()
 
 
+def test_stats_county_is_sent_in_the_us_state_county_form(httpx_mock):
+    _mock_stats(httpx_mock, "observationIntervals")
+
+    get_stats_date_range(county=["Dane", "025", 55021], state="WI")
+
+    (req,) = httpx_mock.get_requests()
+    qs = parse_qs(urlsplit(str(req.url)).query)
+    # Deduplicated, in order; state named the counties' state, so no state_code.
+    assert qs["county_code"] == ["US:55:025", "US:55:021"]
+    assert "state_code" not in qs
+
+
+@pytest.mark.parametrize("native", ["state_code", "county_code"])
+def test_stats_county_cannot_be_combined_with_a_native_location_parameter(native):
+    with pytest.raises(ValueError, match=f"county and {native} cannot be combined"):
+        get_stats_por(county="55025", **{native: "US:55"})
+
+
 def test_get_stats_por_expanded_false(httpx_mock):
     """``expand_percentiles=False`` keeps the raw ``percentiles`` list column
     instead of expanding it into one row per percentile."""