4 counties indexed. ArcGIS FeatureServer and MapServer URLs, with supported search fields per layer.
| County | Endpoints | Searchable fields | Status | Action |
|---|---|---|---|---|
| King County | 1 | Parcel Identification Number · Major (first 6 of PIN) · Minor (last 4 of PIN) | LIVE | OPEN |
| Snohomish County | 1 | Parcel ID · LRSN (Assessor Account Number) · Owner Name +3 | LIVE | OPEN |
| Spokane County | 1 | Parcel ID Number · Parcel Number (display format) · Site Address | LIVE | OPEN |
| Thurston County | 1 | Parcel Number · Mailing Address Line 1 · Mailing Address Line 2 +2 | LIVE | OPEN |
Washington State parcel data is administered by county assessors operating under the Washington State Department of Revenue, but the state does not maintain a unified public parcel REST endpoint. Each county publishes independently. Washington is notable for a state public records law (RCW 42.56.070(8)) that creates ambiguity about owner-name disclosure on public GIS layers: most county assessors exclude owner name from the public parcel REST service while making the same data available through separate records requests or web portals. Snohomish County is the outlier in the atlas — it exposes OWNERNAME on the public layer.
The Washington State Geographic Information Council (WAGIC) sets GIS standards and runs the WA Geospatial Open Data Portal (geo.wa.gov), but parcel aggregation is not mandated at the state level. Counties that host on ArcGIS Online often publish through the standard Esri infrastructure (services.arcgis.com subdomains), while counties that run their own ArcGIS Server publish on county-owned hostnames. Spokane County runs a separate Open Data catalog (gisdatacatalog-spokanecounty.opendata.arcgis.com). Thurston County runs gisdata-thurston.opendata.arcgis.com. King County uses its own gismaps.kingcounty.gov server. There is no common REST hostname pattern across WA counties, unlike Colorado where all data flows through gis.colorado.gov.
Washington's public records law is often cited by county GIS staff when asked why owner name is not on the public REST layer. King County's parcel MapServer carries only PIN, MAJOR, and MINOR — no owner, no address. Spokane County's FeatureServer has 43 confirmed fields including assessed values, acreage, and property use, but no owner name. Thurston County similarly exposes ADDRESS1 (the mailing address, which is typically the owner's address) but not an owner name field. Snohomish County is the exception: OWNERNAME and TAXPRNAME are both present on the public FeatureServer and owner-name LIKE queries return real results.
King County uses PIN (10-digit, split into MAJOR and MINOR). Spokane uses PID_NUM (numeric) and parcel (display format string). Snohomish uses PARCEL_ID and LRSN (the Assessor Account Number, which differs from the parcel polygon identifier). Thurston uses PARCEL_NO. None of these field names cross over. When building a cross-county Washington query, the only reliable anchor is parcel geometry or situs address — there is no statewide identifier equivalent to Colorado's parcel_id or New York's SWIS_SBL_ID.
Snohomish County's ArcGIS Online FeatureServer is updated three times per week, which is unusually frequent for a county parcel layer. The layer carries 51 fields including OWNERNAME, TAXPRNAME, LRSN, assessed and market values (MKLND, MKIMP, MKTTL), use code, exemption data, and situs address broken into components (SITUSHOUSE, SITUSLINE1, SITUSCITY, SITUSZIP). For Everett and Bellevue-adjacent research where ownership data matters, Snohomish is the most programmatically accessible WA county in the atlas.
Seattle metro (~2.3M residents, FIPS 53033). Largest WA county by population. Public parcel layer exposes PIN, MAJOR, MINOR — geometry only, no owner or address. For ownership data, use the King County Assessor's separate property records system.
Everett/Marysville/Lynnwood area north of Seattle (FIPS 53061). The only atlas WA county with OWNERNAME on the public FeatureServer. 51 fields, updated 3x/week. Query with UPPER(OWNERNAME) LIKE UPPER('%25SMITH%25') — confirmed live.
Eastern Washington's primary metro (FIPS 53063). 43-field FeatureServer with assessed values, acreage, and property use. Owner name excluded per WA records law. Parcel queries by PID_NUM or parcel number confirmed live.
State capital region — Olympia, Lacey, Tumwater (FIPS 53067). Self-hosted FeatureServer on map.co.thurston.wa.us. 45 fields including TOTAL_VALUE, ANNUAL_TAX, YEAR_BUILT, SALE_DATE. ADDRESS1 is mailing address; no owner name field on the public layer.
Snohomish owner search (the only WA atlas county that supports it): ?where=UPPER(OWNERNAME) LIKE UPPER('%25SMITH%25')&outFields=PARCEL_ID,SITUSHOUSE,SITUSLINE1,SITUSCITY,SITUSZIP,OWNERNAME,MKTTL&returnGeometry=false&f=json. King County parcel lookup by PIN: ?where=PIN='0000200001'&outFields=*&f=json. Thurston parcel number search: ?where=PARCEL_NO LIKE '%2521820%25'&outFields=PARCEL_NO,ADDRESS1,SITUS_STRE,SITUS_CITY,TOTAL_VALUE,ANNUAL_TAX&returnGeometry=false&f=json. Spokane parcel by display number: ?where=parcel LIKE '%2535163%25'&outFields=PID_NUM,parcel,site_address,site_city,acreage,assessed_amt&returnGeometry=false&f=json.
Last updated 2026-05-24.
4 Washington counties are indexed in the UrbanKit atlas with verified public REST endpoints: King, Spokane, Snohomish, and Thurston. Snohomish expose owner-name search; King, Spokane, and Thurston index by parcel ID and address only.
Snohomish expose an owner-name field on the public REST layer. Snohomish, for example, uses the OWNERNAME field — a case-insensitive search is ?where=UPPER(OWNERNAME)%20LIKE%20UPPER('%25SMITH%25')&outFields=*&f=json. King, Spokane, and Thurston index by parcel ID and address only, so owner lookups there go through the county assessor or appraiser. Open a county's page here for its full field list and a ready-to-run sample query.
King publishes parcels at https://gismaps.kingcounty.gov/arcgis/rest/services/Property/KingCo_Parcels/MapServer/0 — a MapServer (layer 0). It indexes by Parcel Identification Number, Major (first 6 of PIN), and Minor (last 4 of PIN).
Both. Washington uses a mix: Spokane, Snohomish, and Thurston publish ArcGIS FeatureServer layers, while King use MapServer. Both support /query, so the same owner, parcel-ID, and address lookups work against either.
Listing missing or moved? Tell us — we verify and update weekly.