Public ArcGIS MapServer endpoint for St. Clair County parcel data. URL, supported fields, and a working sample query, copy it, or open it directly in the UrbanKit parcel lookup tool.
https://arcgispublicmap.co.st-clair.il.us/server/rest/services/SCC_parcel_map_data/MapServer/29parcel_numberParcel NumberparcelidParcel IDownerOwner Namesiteadr1Site Address (line 1)sitecitySite CityaddressMailing Addresscurl -s 'https://arcgispublicmap.co.st-clair.il.us/server/rest/services/SCC_parcel_map_data/MapServer/29/query?where=UPPER(owner)%20LIKE%20UPPER('%25SMITH%25')&outFields=parcel_number,parcelid,owner,siteadr1,sitecity&returnGeometry=false&f=json&resultRecordCount=10'https://arcgispublicmap.co.st-clair.il.us/server/rest/services/SCC_parcel_map_data/MapServer/29/query?where=UPPER(owner) LIKE UPPER('%SMITH%')&outFields=parcel_number,parcelid,owner,siteadr1,sitecity&returnGeometry=false&f=json&resultRecordCount=10Open this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| parcel_number | Parcel Number | YES |
| parcelid | Parcel ID | YES |
| owner | Owner Name | YES |
| siteadr1 | Site Address (line 1) | YES |
| sitecity | Site City | YES |
| address | Mailing Address | YES |
St. Clair County is Illinois's 8th most populous (Metro East / Greater St. Louis area, county seat Belleville). The SCC_parcel_map_data MapServer is a 31-layer cadastral service; layer 29 (Parcels, 147k+ features) is the polygon parcel layer with 50+ fields including parcel_number, parcelid, owner, address, address2, cityst, zipcode, siteadr1, siteadr2, sitenum/sitepref/sitename/sitetype/sitesuff/siteunit, sitecity/sitest/sitezip, legal1-4, subdiv, twp/twpname, tcacode, class, landuse. Owner-name search via UPPER() LIKE on owner works. Other layers in the service are annotation layers (layers 0-28) and Roads (layer 30). The county GIS data pricing page notes bulk shapefile/geodatabase downloads are paid; the live REST query API is free.
St. Clair County GIS Department, https://www.co.st-clair.il.us/departments/gis
St. Clair County's Parcels layer exposes parcel identifiers (Parcel Number, Parcel ID), owner names (Owner Name), and address fields (Site Address (line 1), Site City, Mailing Address). Use it for owner-name lookups and address-based parcel searches. All 6 listed fields accept queries. Served as an ArcGIS MapServer layer, which supports query operations but not write operations; 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 St. Clair County actually publishes, not what you might expect from a national standard (there isn't one).
For background, see What is an APN?
arcgispublicmap.co.st-clair.il.us serves St. Clair County, Illinois 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 St. Clair County's MapServer 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.
St. Clair County's layer is hosted by the county on arcgispublicmap.co.st-clair.il.us. Public ArcGIS endpoints rarely rate-limit individual reads, but arcgispublicmap.co.st-clair.il.us 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.