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Abandoned mines › California
Abandoned mine inventory

Abandoned mines in Colusa County, California

Colusa County, California has 80 mine and prospect features on USGS topographic maps published 1904–1989, including 15 mine openings (shafts, adits and air shafts) and 44 prospect pits; 20 of the features carry a name on the map. MSHA's register carries 6 mines in the county with status Abandoned or Abandoned and Sealed.

Every mine and prospect feature the USGS digitized from historical topographic maps covering Colusa 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)
80
Mine openings
15
OSMRE problems unreclaimed
0
MSHA mines marked abandoned
6
20 features carry a name44 prospect pits8 quadrangle maps, published 1904–1989 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
    15 18.8%
  2. Prospect pits and trenches
    shallow exploration diggings that never became a mine
    44 55.0%
  3. Mines and surface workings
    labelled mines, open pits, strip mines, placer and hydraulic workings
    13 16.2%
  4. Quarries, gravel and borrow pits
    construction-material and industrial-mineral extraction
    8 10.0%
Named features on the maps20 named · from the USGS compilation
Name on map Feature
Central Mine Mine
Central Mine Open Pit Mine
Clyde Mine Prospect Pit
Clyde Mine Prospect Pit
Clyde Mine Prospect Pit
Colusa Quarry Quarry
Elgin Mine Adit
Elgin Mine Prospect Pit
Empire Mine Mine Shaft
Manzanita Mine Adit
Manzanita Mine Open Pit Mine
McGillery Quarry Quarry
Mercury Mine Prospect Pit
Rathburn Mine Open Pit Mine area
Rathburn Mine Open Pit Mine
Rathburn Mine Prospect Pit
Ruby King Mine Adit
Ruby King Mine Adit
Wide Awake Mine Open Pit Mine
Wide Awake Mine 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.

MSHA-registered mines with status Abandoned6 on register
  1. Arbuckle Rock Products Ltd
    Surface metal/non-metal · Arbuckle Rock Products Ltd · MSHA ID 0405124
    Abandoned
  2. Brownstone Quarry
    Surface metal/non-metal · Brownstone Quarry · MSHA ID 0405453
    Abandoned
  3. Cortina Mill
    Facility metal/non-metal · Cortina Rock Products · MSHA ID 0401744
    Abandoned
  4. GRAVEL PLANT
    Surface metal/non-metal · Robert C Cousineau · MSHA ID 0405298
    Abandoned
  5. O'Sullivan Ranch Pit
    Surface metal/non-metal · Clearlake Redi-Mix Inc · MSHA ID 0405273
    Abandoned
  6. Princeton Ranch Pit
    Surface metal/non-metal · Princeton Ranch · MSHA ID 0404316
    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
Prospect Pit 44
Adit 14
Open Pit Mine 7
Quarry 5
Open Pit Mine 3
Open Pit Mine or Quarry 2
Gravel Pit 2
Mine 1
Mine Shaft 1
Borrow Pit 1
Other counties in CaliforniaAll 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.