Land records · Parcel maps · October 6, 2026
How to Find Old Plat Maps and County Atlases
How to find old plat maps: check the county recorder's plat books, historic county atlases, state libraries, digital map collections, and GLO plats.
How to find old plat maps depends on which kind of plat you need. Recorded subdivision plats, the legal maps that created lots, are kept by the county recorder or register of deeds in plat books or plat cabinets, often going back to the late 1800s. Historic county atlases and land ownership plat books, published commercially, show farm ownership by township and are held by libraries and digital collections. Original government survey plats for public-land states are available from the Bureau of Land Management’s GLO records. This page is general land-records background, not legal advice.
Three kinds of old plats
| Type | What it shows | Where to look |
|---|---|---|
| Recorded subdivision plat | Lots, blocks, streets, easements | County recorder plat books |
| County atlas or land ownership plat book | Owner names on rural tracts | Libraries, archives, digital collections |
| Government survey (GLO) plat | Township and section lines | BLM GLO records, state archives |
Recorded subdivision plats
Ask the county recorder for the plat by subdivision name, or by plat book and page from a deed. Many recorders have scanned plat books and offer them online, even if their deed index only goes back a few decades. Older plats may be in large-format books or on aperture cards. If you know only the address, use the assessor or GIS to find the subdivision name first. See how to find a plat from a street address.
County atlases and plat books
Beginning in the mid-1800s, private publishers produced county atlases with maps of each township showing landowners, farm boundaries, schools, churches, and roads. Twentieth-century land ownership plat books continued the tradition, often updated every few years. Sources include:
- State libraries and historical societies.
- University map libraries.
- Library of Congress digital map collections.
- Large private digital map collections that are free to view.
- Local libraries and county extension offices.
These are excellent for genealogy and tracing farm ownership, though they are not legal surveys.
GLO plats
In states surveyed under the Public Land Survey System, the original township plats from the General Land Office show section lines, waterways, and sometimes early improvements. The BLM GLO records website has scanned plats and field notes for many states. See what is a GLO plat.
Urban maps
For cities and towns, Sanborn fire insurance maps show building footprints and construction materials going back to the late 1800s. See sanborn maps.
Search tips
- Note the township, range, and section, or the subdivision name.
- Search by both current and historic place names.
- Check the parent county if the county was formed later.
- Look for replats and vacations that changed an older plat. See what is a subdivision plat.
Using old plats today
Old recorded plats remain legally relevant for lot lines and easements unless vacated or replatted. Atlas maps are helpful context but not authoritative boundaries. For a boundary question, a licensed surveyor will research recorded plats and monuments.
Ordering copies
Recorders sell certified or uncertified copies, often by the sheet. Libraries may provide scans or allow photography. Large plats may require special printing.
Bottom line
Old recorded plats are at the county recorder, historic county atlases and plat books are in libraries and digital map collections, and original GLO plats are on the BLM’s records site. Use recorded plats for legal lot lines and atlases for ownership history. Find county recorders via the Platbookmapper map.
How to find old plat maps FAQ
Where can I find old plat maps for free?
Many recorder sites, the BLM GLO records site, and digital library collections are free.
What is a county plat book?
A published atlas showing landowners and tract boundaries by township.
Are old plat maps still legally valid?
Recorded subdivision plats generally are unless vacated or replatted.
How do I find the plat for my subdivision?
Get the subdivision name or plat book and page from your deed, then ask the recorder.
What is the difference between a plat map and a county atlas?
A recorded plat creates lots legally; an atlas is a published reference map.