The land ownership data comes from the state/county Cadastral and is only as accurate as the cadastral. I have seen where a surveyed corner was 50' off from the GPS coordinates. Probably would not result in a trespassing citation as game wardens and such use the same data base, but can make a significant difference in a legal access claim and/or whether a parcel of land can be insured with title insurance in a land transaction without additional proof of survey.
