Abandoned mines in Mono County, California

1. Mine openings

   shafts, adits, air shafts, portals and vertical openings: the ways into underground workings
   530 18.0%
2. Prospect pits and trenches

   shallow exploration diggings that never became a mine
   2,136 72.5%
3. Mines and surface workings

   labelled mines, open pits, strip mines, placer and hydraulic workings
   67 2.3%
4. Quarries, gravel and borrow pits

   construction-material and industrial-mineral extraction
   130 4.4%
5. Dumps, tailings, spoil and gob

   what mining left above ground
   83 2.8%

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. Beauregard

   Underground metal/non-metal · Mammoth Lakes Mining Corp · MSHA ID 0404513
   Abandoned 1988-06-15
2. Black Rock Mine

   Underground metal/non-metal · Koppen Mining Construction Corp · MSHA ID 0404239
   Abandoned 1979-05-22
3. Briney Mine

   Underground metal/non-metal · Briney Foundation · MSHA ID 0404886
   Abandoned 1988-06-22
4. Cain Ranch Crusher

   Surface metal/non-metal · Sierra Nevada Construction Inc. · MSHA ID 0405757
   Abandoned 2008-10-10
5. Frank Sam Mine (U S Pumice Mine)

   Surface metal/non-metal · United States Pumice Company · MSHA ID 0404225
   Abandoned 2023-05-30
6. Gorilla Mine

   Underground metal/non-metal · Gorilla Milling & Mining Company · MSHA ID 0404703
   Abandoned 1984-07-31
7. Hilton Creek Mine

   Underground metal/non-metal · Martin Trost Associates · MSHA ID 0404461
   Abandoned 1982-04-20
8. Hunewill Crushing Plant

   Surface metal/non-metal · H E Hunewill Construction Company Inc · MSHA ID 0404728
   Abandoned 1985-07-08
9. Lee Vining Aggregate Plant

   Surface metal/non-metal · Granite Construction Company · MSHA ID 0405234
   Abandoned 2025-03-13
10. Log Cabin Mine

    Underground metal/non-metal · United States Tile Company · MSHA ID 0404328
    Abandoned 1981-11-09
11. Mammoth Creek Pit

    Surface metal/non-metal · Sierra Materials Inc · MSHA ID 0401948
    Abandoned 1982-10-01
12. May Lundy

    Underground metal/non-metal · Lakeview Partners · MSHA ID 0404520
    Abandoned 1982-09-27
13. PINE CREEK MINE

    Underground metal/non-metal · Avocet Tungsten Inc · MSHA ID 0400899
    Abandoned 2019-08-05
14. Plant #1 - Dunmovin

    Surface metal/non-metal · Desert Construction Company · MSHA ID 0404411
    Abandoned 1986-07-15
15. Sierra Quarry

    Surface metal/non-metal · Hunewill Ready Mix Company · MSHA ID 0404715
    Abandoned 1984-10-12
16. Siltex Pit & Pacific Mine

    Surface metal/non-metal · Standard Industrial Minerals Inc · MSHA ID 0404440
    Abandoned 1982-04-20
17. Syndicate Mine

    Facility metal/non-metal · Syndicate Development Inc · MSHA ID 0404617
    Abandoned 1984-09-13
18. U S Pumice Mill

    Facility metal/non-metal · United States Pumice Company · MSHA ID 0401049
    Abandoned 2010-01-01

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
• Siskiyou County 2,362
• Imperial County 1,232
• Mariposa County 1,079
• Tuolumne County 948
• 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.