Abandoned mines in Tuolumne County, California

1. Mine openings

   shafts, adits, air shafts, portals and vertical openings: the ways into underground workings
   441 46.5%
2. Prospect pits and trenches

   shallow exploration diggings that never became a mine
   264 27.8%
3. Mines and surface workings

   labelled mines, open pits, strip mines, placer and hydraulic workings
   42 4.4%
4. Quarries, gravel and borrow pits

   construction-material and industrial-mineral extraction
   61 6.4%
5. Dumps, tailings, spoil and gob

   what mining left above ground
   139 14.7%
6. Mills, tipples and facilities

   processing plants and hazardous structures
   1 0.1%

A name is the label printed beside the symbol on the map. "First mapped" is the earliest topographic edition that shows the symbol, which bounds the feature's age from above; it is not the date it was worked. Unnamed features (most prospect pits, adits and shafts carry no label) are in the counts above but not this list.

1. Alto Mine

   Surface metal/non-metal · Glamis Gold Inc · MSHA ID 0405103
   Abandoned 1993-11-15
2. Columbia Portable

   Surface metal/non-metal · Sierra Rock · MSHA ID 0405193
   Abandoned 1995-07-10
3. Columbia Quarry

   Surface metal/non-metal · Marine Magnesium Company · MSHA ID 0402297
   Abandoned 1995-03-28
4. Haigh Quarry

   Surface metal/non-metal · Sunset Materials · MSHA ID 0402341
   Abandoned 1978-01-31
5. Jacmar Quarry

   Surface metal/non-metal · Jacmar Communications Construction Inc · MSHA ID 0404987
   Abandoned 1994-10-05
6. Jamestown Mine

   Surface metal/non-metal · Sonora Mining Corp · MSHA ID 0404695
   Abandoned 1994-08-03
7. KEYSTONE MILL

   Facility metal/non-metal · Bedford Aggregates · MSHA ID 0402347
   Abandoned 2009-08-24
8. Marine Dolomite Mill

   Facility metal/non-metal · Marine Magnesium Company · MSHA ID 0403493
   Abandoned 1995-06-27
9. Mc Alpine Mine

   Underground metal/non-metal · Jerry Dubson Partner · MSHA ID 0404515
   Abandoned 1981-09-09
10. Montezuma Sand & Gravel

    Surface metal/non-metal · Sierra Rock Products · MSHA ID 0405165
    Abandoned 2025-03-13
11. Omega Mine

    Underground metal/non-metal · G P Mining Company · MSHA ID 0404536
    Abandoned 1991-12-26
12. Optimist Mining Co

    Underground metal/non-metal · Optimist Mining Co · MSHA ID 0404584
    Abandoned 1982-06-08
13. Portable Plant #2

    Surface metal/non-metal · Ford Construction Company Inc · MSHA ID 0405759
    Abandoned 2009-11-17
14. Sarbo Claim

    Underground metal/non-metal · N F Sarbo & D R Langenberg · MSHA ID 0404472
    Abandoned 1981-09-15
15. Sonora Black Quarry

    Surface metal/non-metal · Sonora Aggregates Corp · MSHA ID 0402350
    Abandoned 1978-03-17
16. Sonora Mill And Quarries

    Facility metal/non-metal · Sonora Aggregates Corp · MSHA ID 0402351
    Abandoned 1991-08-05
17. Sonora White Quarry

    Surface metal/non-metal · Sonora Aggregates Corp · MSHA ID 0400272
    Abandoned 1978-03-17
18. Star King

    Underground metal/non-metal · Star King Mining Company · MSHA ID 0404882
    Abandoned 1989-07-11
19. Sundborg Quarry And Mill

    Surface metal/non-metal · Architectural Aggregates · MSHA ID 0403006
    Abandoned 1979-01-18
20. Watsons Wood Creek Mill

    Facility metal/non-metal · R D Watson Inc · MSHA ID 0404266
    Abandoned 1978-12-14

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

• San Bernardino County 14,976
• Inyo County 11,475
• Kern County 4,879
• Riverside County 3,227
• Mono County 2,946
• Siskiyou County 2,362
• Imperial County 1,232
• Mariposa County 1,079
• San Diego County 901
• Calaveras County 840
• Shasta County 832
• Trinity County 685

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.