Mineral Survey, PLSS Definition

Mineral surveys are special federal surveys conducted on mining claims located on public land. Unlike the standard PLSS rectangular grid, which divides land into townships and sections regardless of topography or resource location, mineral surveys follow the actual boundaries of a mining claim, which can be irregular polygons oriented along ore veins, lode deposits, or placer ground.

The legal authority for mineral surveys comes from the General Mining Law of 1872, which allowed citizens to locate and patent hard-rock mining claims on federal land. To obtain a patent, a claimant had to have the claim surveyed by a federally appointed mineral surveyor. The survey was assigned a Mineral Survey number (e.g., "Mineral Survey No. 1247") unique within the state or territory. These numbers, not township-range descriptions, are the primary identifier for patented mining claims.

A mineral survey description typically includes the corners and boundary lines of the claim, the name of the claim (e.g., "Lucky Strike Lode Mining Claim"), the MS number, the state and county, and a tie to a nearby PLSS corner for geographic reference. The tie-in allows the mining claim to be located on a standard PLSS map even though its boundaries don't follow section lines.

Many patented mining claims in western states — particularly in Colorado, Nevada, Idaho, Montana, and Arizona — appear in county deed records as conveyances of "Mineral Survey No. XXXX" with the claim name. When these parcels appear in title chains, the BLM General Land Office Records database contains the original patent and survey plat showing the exact boundaries. For GPS conversion purposes, mineral survey parcels require cadastral data rather than geometric calculation from township-range coordinates.