Public ArcGIS FeatureServer endpoint for McHenry County parcel data. URL, supported fields, and a working sample query — copy it, or open it directly in the UrbanKit parcel lookup tool.
https://services1.arcgis.com/6iYC5AXXYapRVNzl/arcgis/rest/services/McHenry_County_TaxParcels/FeatureServer/0ParcelNumberParcel NumberOwnerOwnerSiteAddressSite AddressSiteAddressCitySite Address CityMailToAddress1Mailing Address (line 1)curl -s 'https://services1.arcgis.com/6iYC5AXXYapRVNzl/arcgis/rest/services/McHenry_County_TaxParcels/FeatureServer/0/query?where=UPPER(Owner)%20LIKE%20UPPER('%25SMITH%25')&outFields=ParcelNumber,Owner,SiteAddress,SiteAddressCity&returnGeometry=false&f=json&resultRecordCount=10'https://services1.arcgis.com/6iYC5AXXYapRVNzl/arcgis/rest/services/McHenry_County_TaxParcels/FeatureServer/0/query?where=UPPER(Owner) LIKE UPPER('%SMITH%')&outFields=ParcelNumber,Owner,SiteAddress,SiteAddressCity&returnGeometry=false&f=json&resultRecordCount=10Open this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| ParcelNumber | Parcel Number | YES |
| Owner | Owner | YES |
| SiteAddress | Site Address | YES |
| SiteAddressCity | Site Address City | YES |
| MailToAddress1 | Mailing Address (line 1) | YES |
| PropertyClass | Property Class | NO |
McHenry County (northernmost Illinois collar county, bordering Wisconsin; county seat Woodstock, pop. 315,000) includes Crystal Lake, Elgin (partial), and the Fox River corridor. The legacy on-prem server at mchenrycountygis.org/arcgis/rest/services/parcels/MapServer was firewalled (HTTP 403) in early 2026. The replacement is now hosted on the county's ArcGIS Online open-data hub at data-mchenrycountygis.opendata.arcgis.com, with the McHenry_County_TaxParcels FeatureServer (services1.arcgis.com/6iYC5AXXYapRVNzl) as the canonical public endpoint. The license is 'open-data', permitting unrestricted use. Roughly 150k parcels, 50+ fields including ParcelNumber, Owner (owner name, searchable via UPPER() LIKE), MailToAddress1, MailToAddress2, MailToCity, MailToState, MailToZip, SiteAddress, SiteAddressHouseNumber, SiteAddressStreetName, SiteAddressStreetType, SiteAddressSuffix, SiteAddressCity, SiteAddressZip, PropertyClass, TaxStatus, and taxing-district assignment fields (Library, ParkDistrict, FireDistrict, GradeSchoolDistrict, HighSchoolDistrict). Owner field exposes the legal owner name; MailToAddress reflects the billing addressee, which may differ for trusts and entities. The open-data hub at data-mchenrycountygis.opendata.arcgis.com has bulk download links for the same dataset.
McHenry County GIS — https://data-mchenrycountygis.opendata.arcgis.com/
McHenry County's McHenry County TaxParcels layer exposes a parcel identifier (Parcel Number), owner names (Owner), and address fields (Site Address, Site Address City, Mailing Address (line 1)). Use it for owner-name lookups and address-based parcel searches. 5 of 6 listed fields accept queries; the rest are returned on read but not indexed for search. 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 McHenry County actually publishes — not what you might expect from a national standard (there isn't one).
For background, see What is an APN?
Many county servers allow public reads but block browser cross-origin requests. The UrbanKit parcel lookup tool fetches directly from your browser; if it works there, the layer is technically public. For your own integration, you may need a same-origin proxy or server-side fetch.
Possibly — counties move services without warning. We re-verify entries weekly and flag stale ones. If you're seeing a fresh 404, please let us know and we'll update the listing.
Most are. Public ArcGIS layers don't typically rate-limit individual reads, but heavy programmatic use can trigger throttling at the host level. Be respectful — query what you need.