Wyoming Abandoned Mine Maps

Every office on this page was opened and checked on Oct. 22, 2026.

The 437 underground mine openings in Wyoming are spread across 23 counties, and the heaviest of them is Fremont County with 113. An opening on a historical sheet is a shaft, an adit or a tunnel that was drawn where the surveyor found it, so it marks a way into workings that run on underground, away from the point.

No public mine map viewer was found; the AML Division at 1-800-510-0283 answers whether a property is over or near a mined area.

No guarantee

Everything here can be wrong. This is information, not a guarantee: the two federal files can be wrong, incomplete or out of date, the boundaries and the geocoder can be wrong, a point is a location and not a property line, and nothing on this page says that a mine is or is not under any particular property. Do not buy, sell, move, or make any decision about a home or about your safety on this alone. Ask the state mine map office named here for the maps, and have a qualified engineer look at the ground.

Wyoming publishes no mine map viewer of its own, so the federal archive is the route.

OSMRE National Mine Map Repository is the federal archive. It holds maps of more than 275,000 closed and abandoned mines, the images are not downloadable, and they are sent on request: search the repository by state, county, company or mine name, then ask for the sheet by its number through the map request form or at nmmr@osmre.gov.

A mine map is the only document that shows the rooms, the pillars and the depth of cover under a given piece of ground. A point in either federal file is a location, not a property line, and it says nothing about what lies under any particular house.

Wyoming runs one of its own. Wyoming Mine Subsidence Insurance Program (DEQ AML) is the programme. State run cover for homes and businesses over or near mined areas: $2 per $1,000 of cover for a house, up to $275,000 per structure, with the claim form and payment on the page.

No public mine map viewer was found; the AML Division at 1-800-510-0283 answers whether a property is over or near a mined area.

A standard homeowner policy excludes earth movement, and mine subsidence is earth movement, so cover for it is bought separately. Ask for the rate on your own address and ask what the policy pays for: the structure, the contents, the land, or only some of them.

The topographic file holds 6,852 mapped mine features inside Wyoming, 437 of them underground openings. The sheets they were drawn on were surveyed between 1949 and 1998. The commonest kinds are gravel pit, prospect pit and adit.

The mineral file holds 4,010 worked or prospected sites in Wyoming, 2,803 of them named, with 1,124 sites recorded as a past producer. The commodities most often named are uranium, sand and gravel and gypsum-anhydrite.

How the counting was done: every point in both files was placed inside the Census TIGER 2024 county and place boundaries by its own coordinates, not by the county name written in the file, because that name is blank or wrong often enough to matter. A point that falls outside every boundary is counted in no county and no town.

What the counts are not: a count of mines under houses. A single opening can lead to workings that run for miles, and a working with no opening on a sheet is in no count at all. Only a mine map shows the rooms, and only the offices named above hold the maps.

No guarantee

Everything here can be wrong. This is information, not a guarantee: the two federal files can be wrong, incomplete or out of date, the boundaries and the geocoder can be wrong, a point is a location and not a property line, and nothing on this page says that a mine is or is not under any particular property. Do not buy, sell, move, or make any decision about a home or about your safety on this alone. Ask the state mine map office named here for the maps, and have a qualified engineer look at the ground.