Abandoned mines in Dewey County, South Dakota

1. Mines and surface workings

   labelled mines, open pits, strip mines, placer and hydraulic workings
   1 1.6%
2. Quarries, gravel and borrow pits

   construction-material and industrial-mineral extraction
   24 37.5%
3. Dumps, tailings, spoil and gob

   what mining left above ground
   19 29.7%
4. Other reclamation problems

   highwalls, subsidence, polluted or clogged water, fires, slides and gases in OSMRE's inventory
   20 31.2%

Problem types carry OSMRE's priority prefix: P1 and P2 are threats to health, safety and property, P3 is environmental. A problem area is a cluster of problems reclaimed as one project; several rows can share one location.

1. Bear Creek Pit

   Surface metal/non-metal · Dewey County Highway Department · MSHA ID 3900919
   Abandoned 1978-12-06
2. Billy Alley Pit

   Surface metal/non-metal · Dewey County Highway Department · MSHA ID 3901083
   Abandoned 1978-12-06
3. Cheyenne River Pit

   Surface metal/non-metal · Bureau Of Indian Affairs · MSHA ID 3901173
   Abandoned 1985-05-01
4. Dewey County Mines

   Surface metal/non-metal · Dewey County Highway Department · MSHA ID 3900847
   Abandoned 1982-08-17
5. Isobel

   Surface coal · Isobel Coal Company · MSHA ID 3901294
   Abandoned and Sealed 1986-02-19
6. Max Schriock Crusher

   Surface metal/non-metal · Schriock Construction Inc · MSHA ID 3901310
   Abandoned 1985-07-03

Status and date are as reported to MSHA by the operator. Each mine's own page carries its accident, citation and inspection record.

• Lawrence County 295
• Pennington County 163
• Edmunds County 150
• Custer County 131
• McPherson County 127
• Roberts County 124
• Beadle County 123
• Codington County 120
• Tripp County 120
• Brookings County 112
• Minnehaha County 109
• Turner County 97

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national inventory of abandoned mine features, and that the detailed national database now being built will not be published.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.