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Abandoned mines › California
Abandoned mine inventory

Abandoned mines in Napa County, California

Napa County, California has 166 mine and prospect features on USGS topographic maps published 1942–1993, including 28 mine openings (shafts, adits and air shafts) and 53 prospect pits; 34 of the features carry a name on the map. MSHA's register carries 7 mines in the county with status Abandoned or Abandoned and Sealed.

Every mine and prospect feature the USGS digitized from historical topographic maps covering Napa 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)
166
Mine openings
28
OSMRE problems unreclaimed
0
MSHA mines marked abandoned
7
34 features carry a name53 prospect pits18 quadrangle maps, published 1942–1993 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
    28 16.9%
  2. Prospect pits and trenches
    shallow exploration diggings that never became a mine
    53 31.9%
  3. Mines and surface workings
    labelled mines, open pits, strip mines, placer and hydraulic workings
    28 16.9%
  4. Quarries, gravel and borrow pits
    construction-material and industrial-mineral extraction
    48 28.9%
  5. Dumps, tailings, spoil and gob
    what mining left above ground
    9 5.4%
Named features on the maps34 named · from the USGS compilation
Name on map Feature
Aetna Extension Prospect Pit
Aetna Mine Adit
Aetna Mine Mine
Aetna Mine Extension Prospect Pit
Asbestos Mine Open Pit Mine
Bella Oak Mine Adit
Blue Monday Mine Adit
Buckhorn Mine Open Pit Mine
Corona Mine Adit
Corona Mine Open Pit Mine
Ivanhoe Prospect Pit
Kellet Prospect Pit
Kellet Mine Adit
Knoxville Mine Shaft
Knoxville (Site) Adit
LaJoya Quicksilver Mine Adit
Manhattan Mine Open Pit Mine
Manhattan Mine Prospect Pit
McLaughlin Mine Open Pit Mine
McLaughlin Mine Tailings - Undifferentiated area
Oat Hill Extension Mine Adit
Oat Hill Extention Mine Open Pit Mine
Oat Hill Mine Adit
Oat Hill Mine Open Pit Mine
Palisade Mine Adit
Palisade Mine Open Pit Mine
Quick Silver Mine Open Pit Mine
Silverado Mine Open Pit Mine
Silverado Mine Prospect Pit
Toyon Mine Adit
Toyon Mine Open Pit Mine
Twin Peaks Mine Open Pit Mine
Twin Peaks Mine Prospect Pit
White Rock 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 Abandoned7 on register
  1. American Canyon
    Surface metal/non-metal · Amos & Andrews Inc · MSHA ID 0404863
    Abandoned
  2. Blue Rock
    Surface metal/non-metal · Don Wesner Inc. · MSHA ID 0405519
    Abandoned
  3. Gardners Rock
    Surface metal/non-metal · Gardner'S Rock Company · MSHA ID 0402181
    Abandoned
  4. Manhattan Mine
    Surface metal/non-metal · One Shot Mining Company · MSHA ID 0400868
    Abandoned
  5. Napa Shop
    Facility metal/non-metal · Syar Industries Inc · MSHA ID 0405242
    Abandoned
  6. Ray'S Base Plant
    Surface metal/non-metal · Rays Rock Sand & Gravel Company · MSHA ID 0403391
    Abandoned
  7. Sulphur Creek Sand And Gravel
    Surface metal/non-metal · Harold Smith & Son Inc · MSHA ID 0401799
    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 53
Adit 25
Quarry 17
Open Pit Mine or Quarry 13
Open Pit Mine 13
Gravel/Borrow Pit - Undifferentiated 10
Gravel Pit 9
Tailings - Pond 8
Quarry 6
Gravel/Borrow Pit - Undifferentiated 4
Mine Shaft 3
Quarry - Rock 1
Tailings - Undifferentiated 1
Quarry - Rock 1
Mine 1
Disturbed Surface 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.