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Abandoned mines › Colorado
Abandoned mine inventory

Abandoned mines in Dolores County, Colorado

Dolores County, Colorado has 270 mine and prospect features on USGS topographic maps published 1953–1994, including 157 mine openings (shafts, adits and air shafts) and 73 prospect pits; 24 of the features carry a name on the map. OSMRE's abandoned mine land inventory lists 5 problems in the county, 3 of them not yet reclaimed. MSHA's register carries 10 mines in the county with status Abandoned or Abandoned and Sealed.

Every mine and prospect feature the USGS digitized from historical topographic maps covering Dolores County, every OSMRE abandoned mine land problem in the county, and every MSHA-registered mine here with status Abandoned. Named features are listed below; unnamed ones are counted by type. Locations are deliberately not shown: this page says what abandoned workings are in the county, not where to find them. They are dangerous and should not be entered.

Mapped mine features (USGS)
270
Mine openings
157
OSMRE problems unreclaimed
3
MSHA mines marked abandoned
10
24 features carry a name73 prospect pits14 quadrangle maps, published 1953–1994 5 OSMRE problems, 2 reclaimed 0 MSHA mines abandoned and sealed
What the features are
  1. Mine openings
    shafts, adits, air shafts, portals and vertical openings: the ways into underground workings
    160 58.2%
  2. Prospect pits and trenches
    shallow exploration diggings that never became a mine
    73 26.5%
  3. Mines and surface workings
    labelled mines, open pits, strip mines, placer and hydraulic workings
    1 0.4%
  4. Quarries, gravel and borrow pits
    construction-material and industrial-mineral extraction
    32 11.6%
  5. Dumps, tailings, spoil and gob
    what mining left above ground
    7 2.5%
  6. Other reclamation problems
    highwalls, subsidence, polluted or clogged water, fires, slides and gases in OSMRE's inventory
    2 0.7%
Named features on the maps24 named · from the USGS compilation
Name on map Feature
ABG Mine Adit
Aztec Mine Adit
Blue Bell Mine Adit
Emma Mine Mine Dump area
Emma Mine Mine Shaft
Enterprise Mine Adit
Expectation Mine Adit
Jones Mine Adit
Laura Mine Mine Shaft
Lexington Mine Adit
Logan Mine Adit
Mtn Spring Mine Mine Shaft
Nora Lily Mine Mine Shaft
Puzzle Mine Mine Shaft
Revenue Mine Adit
Rock of Ages Mine Adit
Sambo Mine Adit
Silver Glance Mine Mine Shaft
Silver Swan Mine Adit
Smuggler Mine Adit
Smuggler Mine Mine Dump area
Sunflower Mine Adit
Union Carbonate Mine Mine Shaft
Worlds Fair Prospect Prospect Pit

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.

OSMRE abandoned mine land problems5 on inventory
Problem area Problem Status
Dolores - Non-coal-county-wide P1 Portals In Reclamation
Dolores - Non-coal-county-wide P1 Vertical Openings In Reclamation
Dolores - Non-coal-county-wide P1 Vertical Openings Reclamation Completed
Dolores County - Coal - Co-wide P3 Mine Opening Reclamation Pending
New Mexico/north Star - 28/69-01 P1 Underground Mine Fires Reclamation Completed

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.

MSHA-registered mines with status Abandoned10 on register
  1. Cone Crushing Plant
    Surface metal/non-metal · Mountain Gravel & Construction Company · MSHA ID 0503306
    Abandoned
  2. CROSS CANYON QUARRY #2
    Surface metal/non-metal · H & H Stone Inc · MSHA ID 0504698
    Abandoned
  3. Emma Mine
    Underground metal/non-metal · Dolores Canyon Mines Inc · MSHA ID 0503605
    Abandoned
  4. Iron Clad
    Underground metal/non-metal · Myron Jones · MSHA ID 0502784
    Abandoned
  5. Little Silver
    Underground metal/non-metal · James J Costello · MSHA ID 0503878
    Abandoned
  6. Mc Phee Reservoir Pit
    Surface metal/non-metal · U S Bureau Of Reclamation · MSHA ID 0504093
    Abandoned
  7. Rico Complex
    Underground metal/non-metal · Anaconda Minerals Company · MSHA ID 0500416
    Abandoned
  8. Rico-Argentine Leaching
    Facility metal/non-metal · Rico-Argentine Mining Company · MSHA ID 0502759
    Abandoned
  9. Rose Bud
    Underground metal/non-metal · Trinity Mining Company · MSHA ID 0503503
    Abandoned
  10. White & Sons Construction Incorporated
    Surface metal/non-metal · White & Sons Construction Inc · MSHA ID 0503961
    Abandoned

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

By source vocabularythe publishers' own terms
Feature type Features
Adit 128
Prospect Pit 73
Mine Shaft 29
Gravel Pit 25
Gravel Pit 7
Mine Dump 5
Settling Pond 2
P1 Vertical Openings 2
P1 Portals 1
Open Pit Mine 1
P3 Mine Opening 1
P1 Underground Mine Fires 1
Other counties in ColoradoAll counties →
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 as a working mine, and the map does not say which. An OSMRE row is a problem the abandoned mine land program tracks, not a mine. An MSHA mine is a registered operation whose operator reported abandonment, a record that starts in the 1970s. The three overlap and are never added together. The county is assigned from each feature's coordinates against the Census 2023 county boundaries. The full method is 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.