Public ArcGIS FeatureServer endpoint for Sonoma County parcel data. URL, supported fields, and a working sample query, copy it, or open it directly in the UrbanKit parcel lookup tool.
https://socogis.sonomacounty.ca.gov/map/rest/services/OWTSPublic/Cities_GIS_Parcel_Base/FeatureServer/0APNAssessor's Parcel NumberSitusFormatted1Situs Address (line 1)SitusStreetNameSitus Street NameSitusCitySitus Citycurl -s 'https://socogis.sonomacounty.ca.gov/map/rest/services/OWTSPublic/Cities_GIS_Parcel_Base/FeatureServer/0/query?where=APN%3D%27029-201-001%27&outFields=APN,SitusFormatted1,SitusStreetName,SitusCity&f=json'
https://socogis.sonomacounty.ca.gov/map/rest/services/OWTSPublic/Cities_GIS_Parcel_Base/FeatureServer/0/query?where=APN='029-201-001'&outFields=APN,SitusFormatted1,SitusStreetName,SitusCity&f=jsonOpen this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| APN | Assessor's Parcel Number | YES |
| SitusFormatted1 | Situs Address (line 1) | YES |
| SitusStreetName | Situs Street Name | YES |
| SitusCity | Situs City | YES |
Sonoma County (county seat Santa Rosa, pop. 490,000) publishes parcels through the OWTSPublic Cities_GIS_Parcel_Base FeatureServer. APN format is XXX-XXX-XXX with hyphens (e.g. '029-201-001'). Owner name is NOT exposed on this public layer, California Government Code §7928.205 restricts owner and mailing-address data from public REST endpoints. For ownership data, use the Sonoma County Assessor's parcel search at sonomacounty.ca.gov/assessor. The address schema on this layer was refactored in 2026: the prior single SitusAddress string field was replaced by two formatted address lines (SitusFormatted1, SitusFormatted2) plus fully structured components, SitusStreetNo, SitusDirection, SitusStreetName, SitusStreetType, SitusUnitNumber, SitusCity, SitusState, SitusZip. Queries on the old SitusAddress field name will fail against the current layer; use SitusFormatted1 or SitusStreetName instead. The endpoint is hosted on the county's own ArcGIS server (socogis.sonomacounty.ca.gov). The Sonoma County GIS open-data hub is at gis-sonomacounty.hub.arcgis.com.
Sonoma County GIS, https://gis-sonomacounty.hub.arcgis.com/
Sonoma County's Cities GIS Parcel Base layer exposes a parcel identifier (Assessor's Parcel Number) and address fields (Situs Address (line 1), Situs Street Name, Situs City). Use it for address-to-PIN lookups and identifier queries. All 4 listed fields accept queries. Served as an ArcGIS FeatureServer layer, so edits and applyEdits operations are technically exposed (read access only is published here); last verified 2026-05-15.
/query?where=…&outFields=*&f=jsonto the URL. The sample query above is a working example you can paste into a browser tab to see the raw JSON response.Counties publish parcel data through their own ArcGIS Server installations, each with its own schema. One county uses APN, another uses PIN, a third uses PARCEL_ID. Some expose owner names; others keep them on a separate assessor's portal. The searchable fields list above reflects what Sonoma County actually publishes, not what you might expect from a national standard (there isn't one).
For background, see What is an APN?
socogis.sonomacounty.ca.gov serves Sonoma County, California parcels over public ArcGIS REST, but, like most county servers, it may not send the CORS headers a browser needs for a cross-origin fetch. If a direct browser call fails, the layer still works from curl, Postman, or a server-side script; the UrbanKit parcel lookup tool proxies the request, so a search that succeeds there confirms the layer is genuinely public.
We last verified Sonoma County's FeatureServer layer on 2026-05-15. County GIS teams move services without notice, so if you hit a fresh 404, tell us and we'll re-check. Atlas entries are re-verified on a rolling basis.
Sonoma County's layer is hosted by the county on socogis.sonomacounty.ca.gov. Public ArcGIS endpoints rarely rate-limit individual reads, but socogis.sonomacounty.ca.gov can throttle heavy automated traffic at the host level. Page through results with resultOffset / resultRecordCount and request only the fields you need. There's no API key and no charge from the county.