County Coverage
OpenCMA aggregates public property data across Ohio and California. Counties are organized into tiers based on the depth of data available from their public GIS services. All covered properties also receive nationwide enrichment data. See the About page for a full list of data sources.
Full (6)
Sonoma and Los Angeles have the richest data including sale prices (direct or inferred from documentary transfer tax).
Good (15)
Counties with assessor data including building details, assessed values, and owner information but no sale price disclosure.
Basic (8)
Counties with parcel boundary data, addresses, and APN identifiers from county GIS services.
Not Covered (29)
Remaining California counties have no public GIS endpoints with queryable parcel data. There is no CA equivalent to Ohio's OGRIP statewide database.
Nationwide Enrichment for All Properties
Every covered property -- regardless of tier -- receives FEMA flood zone data, Census ACS demographics, Walk Score ratings, nearby amenities from OpenStreetMap, USGS earthquake history, USFWS wetland data, EPA facility proximity, and Superfund site checks. Ohio properties additionally receive state EPA environmental data, DNR geological resources, and local income tax rates. California properties receive hazard zone classifications, CalEnviroScreen scores, fire history, and sales tax rates.
California Counties
29 of 58 counties are covered. Counties without public GIS endpoints are not queryable.
Dedicated scraper with property details, values, sales data
- Parcel boundaries & geometry
- Owner name, assessed values
- Building details (sqft, beds, baths, year built)
- Sale price data (inferred or direct)
- All state enrichment (hazards, CalEnviroScreen, fire)
Assessor data with building details, no sale prices
- Parcel boundaries & geometry
- Owner name, assessed values
- Building details (sqft, beds, baths)
- No sale price data
- All state enrichment (hazards, CalEnviroScreen, fire)
Parcel boundaries, addresses, and land use codes
- Parcel boundaries & geometry
- Address, APN, basic attributes
- All state enrichment (hazards, CalEnviroScreen, fire)
No county-level data available
- No county-level property data
- Nationwide enrichment only (if geocoded)