Abandoned mines in Summit County, Colorado

1. Mine openings

   shafts, adits, air shafts, portals and vertical openings: the ways into underground workings
   231 15.9%
2. Prospect pits and trenches

   shallow exploration diggings that never became a mine
   1,157 79.6%
3. Mines and surface workings

   labelled mines, open pits, strip mines, placer and hydraulic workings
   13 0.9%
4. Quarries, gravel and borrow pits

   construction-material and industrial-mineral extraction
   15 1.0%
5. Dumps, tailings, spoil and gob

   what mining left above ground
   37 2.5%
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.

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. ALPINE PIT

   Surface metal/non-metal · Alpine Rock Company · MSHA ID 0503051
   Abandoned 2015-10-01
2. Bemrose Placer

   Surface metal/non-metal · Bemrose Mining Company · MSHA ID 0503978
   Abandoned 1985-07-08
3. Bengal Tiger Mine

   Underground metal/non-metal · Strategic American Metals · MSHA ID 0503868
   Abandoned 1984-09-10
4. Big Four Mine

   Underground metal/non-metal · Kellogg Development Corp · MSHA ID 0502309
   Abandoned 1981-08-21
5. Breckenridge Lands Placer

   Surface metal/non-metal · Flatiron Paving Company · MSHA ID 0504018
   Abandoned 1987-08-01
6. Cashier

   Underground metal/non-metal · Windsor Resources (Us) Ltd · MSHA ID 0503861
   Abandoned 1985-04-23
7. Climax Ten Mile Tunnel

   Underground metal/non-metal · Climax Molybdenum Company · MSHA ID 0502255
   Abandoned 2014-08-13
8. Copper Mountain Excavation

   Surface metal/non-metal · Southway Const Co Inc & Asphalt Gravel Prod Inc · MSHA ID 0502738
   Abandoned 1981-07-17
9. Copper Mountain Pit

   Surface metal/non-metal · Flatiron Paving Company · MSHA ID 0503326
   Abandoned 1982-08-04
10. Extec S-5 Track Mounted Screen sn9617

    Surface metal/non-metal · Peak Materials · MSHA ID 0502366
    Abandoned 2022-06-29
11. Fourth National Bank Pit

    Surface metal/non-metal · Flatiron Paving Company · MSHA ID 0503290
    Abandoned 1982-08-04
12. Gilrose

    Surface metal/non-metal · Continental Aggregates Inc · MSHA ID 0503816
    Abandoned 1992-05-14
13. Gold Crest

    Underground metal/non-metal · Hard Rock Mining Company · MSHA ID 0503561
    Abandoned 1982-09-20
14. Harriman Quarry

    Surface metal/non-metal · Simon Contractors · MSHA ID 0504745
    Abandoned 2018-10-02
15. Kokomo Aggregate Plant

    Surface metal/non-metal · C Ryan & Son Inc · MSHA ID 0503165
    Abandoned 1983-09-27
16. Landslide

    Underground metal/non-metal · Mallon Minerals Corp · MSHA ID 0503832
    Abandoned 1983-07-21
17. Mayflower Pit

    Surface metal/non-metal · Plains Aggregate Company · MSHA ID 0502723
    Abandoned 1979-01-19
18. McCloskey portable screen plant

    Surface metal/non-metal · Everist Materials LLC · MSHA ID 0504970
    Abandoned 2013-02-02
19. New York Mine

    Underground metal/non-metal · Marquette Minerals Inc · MSHA ID 0503655
    Abandoned 1982-06-24
20. Portable Crushing Plant #6

    Surface metal/non-metal · Southway Construction Company · MSHA ID 0504849
    Abandoned 2007-05-30
21. PORTABLE SCREEN

    Surface metal/non-metal · Rock Island Project · MSHA ID 0504723
    Abandoned 2002-07-22
22. Red Wing No 1

    Underground metal/non-metal · Red Wing Mining Company Inc · MSHA ID 0503508
    Abandoned 1981-01-19
23. Silver Wing

    Underground metal/non-metal · Moly 1 Corp · MSHA ID 0504317
    Abandoned 1992-06-01
24. Silver Wing Mine

    Underground metal/non-metal · Montezuma Silver Corp · MSHA ID 0503154
    Abandoned 1979-07-23
25. Silverthorne

    Surface metal/non-metal · L G Everist Inc · MSHA ID 0502135
    Abandoned 1983-09-29
26. Silverthorne North

    Surface metal/non-metal · L G Everist Inc · MSHA ID 0500979
    Abandoned 1980-10-30
27. Smith Pit

    Surface metal/non-metal · F J Kent Pipeline Company · MSHA ID 0503963
    Abandoned 1995-06-27
28. Tiger Run

    Surface metal/non-metal · Flatiron Paving Company · MSHA ID 0503677
    Abandoned 1985-08-19
29. Vega Mine

    Underground metal/non-metal · Vega Mining Company · MSHA ID 0502765
    Abandoned 1986-06-25
30. Venus Mine

    Surface metal/non-metal · Silver Core Mining Corp · MSHA ID 0503095
    Abandoned 1981-04-09

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

• San Juan County 3,913
• Lake County 3,672
• Gunnison County 2,703
• Saguache County 2,319
• San Miguel County 2,242
• Gilpin County 2,148
• Montrose County 2,077
• Custer County 2,062
• Clear Creek County 1,996
• Park County 1,624
• Chaffee County 1,486
• Boulder County 1,083

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.