What is a plat map, and where do I find mine?

Question

Turnrow Capital · Accepted Answer

A plat map is the recorded drawing of how land is divided — parcels, dimensions, roads, easements, and lot numbers — maintained by the county recorder or assessor. For PLSS ground, the original government township plats live at the BLM's General Land Office records site, free online. Most counties now publish parcel maps through a GIS portal.

Three map layers serve different jobs. The assessor's parcel map shows tax parcels and APNs — good for orientation, but it is not a survey and often carries the disclaimer to prove it. Recorded subdivision or partition plats are legal documents that can actually govern boundaries and easements. The original GLO township plats and field notes are the root of every PLSS description and still control where lost section corners get re-established.

To find yours: start at the county GIS site (search the county name plus "parcel viewer"), pull the APN and the deed reference, then ask the recorder for any recorded surveys or plats referencing your section. BLM's GLO records site serves scanned original plats and survey field notes by state, township, and range — genuinely useful when a surveyor or attorney is chasing an old corner.

Remember the hierarchy: a recorded plat or survey beats the assessor's lines every time. When the GIS parcel map and a recorded survey disagree — and they often disagree by 10–50 feet — the survey controls. Never price or fence ground off assessor lines alone.