Land records · Parcel maps · October 5, 2026
How to Tell If Land Is Public or Private
How to tell if land is public or private: check county parcel ownership, public land maps, federal and state agency layers, signs, and paint marks.
How to tell if land is public or private: look up the parcel on the county’s GIS parcel viewer or assessor site, which shows ownership, then compare it with public land maps from federal and state agencies that show national forests, Bureau of Land Management land, wildlife areas, and state trust lands. In the field, watch for boundary signs and purple paint, which many states recognize as no trespassing marks. When in doubt, assume land is private. This page is general land-records background, not legal advice.
Records that show ownership
| Source | What it shows |
|---|---|
| County parcel viewer or assessor | Owner name, parcel lines, tax status. See GIS parcel viewer search |
| Federal agency maps | National forests, BLM land, wildlife refuges |
| State agency maps | State parks, wildlife areas, state trust land |
| USGS Protected Areas Database | Nationwide public and protected land layer |
| Recorded plats | Dedicated parks, streets, and public tracts |
Government owners in county records often appear as “United States of America,” a state agency, county, or city. Many publicly owned parcels are tax exempt.
Public ownership is not always public access
- State trust lands may require permits or prohibit recreation in some states.
- Military, utility, and water district land may be closed.
- Landlocked public parcels surrounded by private land may lack legal access.
- Leases on public land, such as grazing or mining, may restrict certain uses. See how to look up a mining claim.
Paper streets and dedicated areas
Plats sometimes dedicate streets or parks that were never built. Their public status can be unclear. See what is a paper street.
Field clues
- Agency boundary signs and brown carsonite posts.
- Purple paint on trees or posts in states with purple paint laws.
- Fences and gates, though fences do not always follow lines.
- Posted signs stating no trespassing.
Phone mapping apps can display parcel lines, but they are not legal surveys. See Google Maps lot lines vs county GIS.
Waterways and shorelines
Rules for walking along rivers, beaches, and lakeshores vary greatly by state. Some states recognize public rights below the high water mark; others do not. Check state law before assuming access.
Why it matters
Trespassing can bring fines and conflicts. Hunters and anglers face specific penalties in many states. Builders and buyers need to know whether adjacent land is public open space or private land that could be developed.
Researching a specific spot
Drop a pin on a county parcel viewer, click the parcel for owner information, then cross-check on an agency map. If ownership looks public but access is unclear, contact the managing agency’s local office.
Bottom line
To tell if land is public or private, check county parcel ownership and compare with federal and state public land maps, then look for signs and purple paint in the field. Public ownership does not always mean open access, so verify rules with the managing agency. Check parcel ownership on the Platbookmapper map.
How to tell if land is public or private FAQ
How can I find out who owns a piece of land?
Look it up on the county assessor or GIS parcel viewer.
Is all government land open to the public?
No. State trust, military, and utility lands may restrict access.
What does purple paint on trees mean?
In many states, it marks no trespassing.
Can I trust phone apps for land boundaries?
They are helpful but not legal surveys.
Can I cross private land to reach public land?
Not without permission or a legal access route.