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← Abandoned mines, all states · Mining incidents in Wyoming
Abandoned mine inventory

Abandoned mines in Wyoming

Wyoming has 7,801 mine and prospect features on USGS topographic maps published 1911–1998, including 515 mine openings (shafts, adits and air shafts), across 23 counties. OSMRE's abandoned mine land inventory lists 2,699 problems in the state, 732 of them not yet reclaimed. MSHA's register carries 736 Wyoming mines with status Abandoned or Abandoned and Sealed.

Every mine and prospect feature the USGS digitized from historical topographic maps of Wyoming, every OSMRE abandoned mine land problem, and every MSHA-registered mine with status Abandoned, by county. Each county page lists the named features and links every MSHA mine to its own record.

Mapped mine features (USGS)
7,801
Mine openings
515
OSMRE problems unreclaimed
732
MSHA mines marked abandoned
736
23 counties with mapped features242 features carry a name4,059 prospect pitsmaps published 1911–1998 2,699 OSMRE problems, 1,967 reclaimed1,066 problem areas (PADs), 351 with work left 21 MSHA mines abandoned and sealed The state program's own inventory estimate: ~3,000-4,000 features; ~1,500 sites (IMCC-NAAMLP Hardrock AML Report 2025, Table 5, page 46).
By countyranked by mapped USGS features
County USGS features Openings OSMRE problems MSHA abandoned
Fremont County
2,398 113 531 69
Crook County
919 39 235 35
Carbon County
713 120 395 51
Sweetwater County
691 41 366 50
Albany County
428 17 169 23
Big Horn County
427 6 88 30
Johnson County
254 11 41 41
Natrona County
231 4 43 33
Lincoln County
212 32 175 27
Converse County
198 29 57 52
Park County
179 37 81 37
Campbell County
179 0 36 69
Laramie County
165 13 29 28
Uinta County
114 10 61 28
Weston County
111 5 49 17
Platte County
111 17 39 15
Sheridan County
104 3 129 40
Hot Springs County
81 3 110 17
Sublette County
80 4 8 25
Goshen County
75 6 25 16
Teton County
57 5 19 20
Niobrara County
44 0 7 5
Washakie County
30 0 6 8
What the features are
  1. Mine openings
    shafts, adits, air shafts, portals and vertical openings: the ways into underground workings
    1,412 13.4%
  2. Prospect pits and trenches
    shallow exploration diggings that never became a mine
    4,059 38.7%
  3. Mines and surface workings
    labelled mines, open pits, strip mines, placer and hydraulic workings
    605 5.8%
  4. Quarries, gravel and borrow pits
    construction-material and industrial-mineral extraction
    2,507 23.9%
  5. Dumps, tailings, spoil and gob
    what mining left above ground
    633 6.0%
  6. Mills, tipples and facilities
    processing plants and hazardous structures
    72 0.7%
  7. Other reclamation problems
    highwalls, subsidence, polluted or clogged water, fires, slides and gases in OSMRE's inventory
    1,150 11.0%
  8. Other
    symbols outside the classes above
    62 0.6%
By source vocabularythe publishers' own terms
Feature type Features
Prospect Pit 4,057
Gravel Pit 855
Gravel Pit 549
Clay Pit 435
P2 Vertical Openings 415
P2 Portals 398
P3 Spoil Area 374
Adit 305
P3 Pits 270
Mine Shaft 207
Disturbed Surface 197
P2 Dangerous Highwalls 186
Clay Pit 176
Gravel/Borrow Pit - Undifferentiated 175
Open Pit Mine 173
P2 Subsidence 165
P3 Mine Opening 98
P3 Slump 92
Quarry 82
P3 Gobs 78
Tailings - Undifferentiated 73
Strip Mine 69
P1 Subsidence 66
P2 Hazardous Equip & Facilities 64
Open Pit Mine 62
Borrow Pit 58
Bentonite Pit 55
P1 Portals 53
P2 Dangerous Piles & Embankments 47
Borrow Pit 46
P2 Underground Mine Fires 44
Open Pit Mine or Quarry 35
P2 Hazardous Water Bodies 34
P2 Clogged Streams 32
P1 Vertical Openings 31
Quarry 29
Mine Dump 28
P3 Equipment Facility 23
Uranium Mine 22
P2 Clogged Stream Lands 22
How to read these numbers

A USGS feature is a symbol on a historical topographic map, there when the map was surveyed; it may since have been sealed, reclaimed, built over or reopened, and the map does not say which. An OSMRE row is a problem the abandoned mine land program tracks, not a mine, and several problems make one problem area (PAD), which is the unit a state program counts and reports; the public extract can also hold more problem areas than a state's live inventory, because areas since merged or ruled ineligible stay in the published file, so a state figure that differs from this one is not a contradiction. An MSHA mine is a registered operation whose operator reported abandonment, a record that starts in the 1970s; that is a regulatory status rather than a physical one, and it also holds operations merely between jobs, portable crushers above all, which is why over a thousand mines carrying it have been inspected in the last two years. The three overlap and are never added together. Counties are assigned from each feature's coordinates against the Census 2023 county boundaries. The full method and every source are on the national page.

Sources
  1. USGS, Consolidated Prospect- and Mine-Related Features from 7.5- and 15-Minute Topographic Quadrangle Maps of the United States (USMIN)
    597,612 point and area features digitized from about 106,350 historical topographic maps published 1886–2006; public domain (CC0). A feature is a map symbol, not a field-verified site, and the map does not say whether it was still worked.
  2. USGS Fact Sheet 2025–3003, The Abandoned Mine Inventory of the United States
    States that as of 2025 there is no comprehensive national inventory of abandoned mine features, and that the detailed national database now being built will not be published.
  3. OSMRE, Abandoned Mine Land Inventory System (e-AMLIS), public Problems layer
    One row per abandoned mine land problem in a problem area, with its type, funding program and reclamation status; mostly coal mined before the 1977 Surface Mining Control and Reclamation Act. Coordinates are the problem area's.
  4. MSHA, Mines dataset (Mine Data Retrieval System)
    Every mine registered with MSHA since the 1970s; a mine reads Abandoned or Abandoned and Sealed when its operator reported that status. Refreshed weekly.
  5. US Census Bureau, 2023 cartographic county boundaries (1:500,000)
    Each feature's county is assigned by its coordinates against these boundaries, not copied from the source file.
  6. GAO-20-238, Abandoned Hardrock Mines (March 2020)
    Federal agencies had identified at least 140,000 abandoned hardrock mine features on federal land and estimated more than 390,000 more not yet captured in their databases.
  7. Abandoned Hardrock Mine Reclamation (AHMR) Program, US Department of the Interior
    The program the USGS inventory is compiled for. Its appropriations and the 674,000 field-confirmed feature count on this page were provided by the program manager, Office of Environmental Policy and Compliance, and are cited with permission (2026-09-08).
  8. IMCC-NAAMLP Hardrock AML Report
    Page 48 carries the two figures this page leans on: USGS estimates 633,181 of the 725,690 mine features it recorded from historic topographic maps, 87 percent, are hardrock; and state and federal agencies have submitted more than 724,000 AML features to the national database being built, already more than the historic maps hold. Year-by-year AHMR funding is on page 35.