Mining Incidents
Abandoned mine inventory

Abandoned mines in Pondera County, Montana

Pondera County, Montana has 101 mine and prospect features on USGS topographic maps published 1934–1985, including 1 mine openings (shafts, adits and air shafts) and 4 prospect pits; 17 of the features carry a name on the map. OSMRE's abandoned mine land inventory lists 11 problems in the county, 2 of them not yet reclaimed. 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 Pondera 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)
101
Mine openings
1
OSMRE problems unreclaimed
2
MSHA mines marked abandoned
7
17 features carry a name4 prospect pits26 quadrangle maps, published 1934–1985 11 OSMRE problems, 9 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
    5 4.5%
  2. Prospect pits and trenches
    shallow exploration diggings that never became a mine
    4 3.6%
  3. Mines and surface workings
    labelled mines, open pits, strip mines, placer and hydraulic workings
    18 16.1%
  4. Quarries, gravel and borrow pits
    construction-material and industrial-mineral extraction
    78 69.6%
  5. Dumps, tailings, spoil and gob
    what mining left above ground
    5 4.5%
  6. Mills, tipples and facilities
    processing plants and hazardous structures
    1 0.9%
  7. Other reclamation problems
    highwalls, subsidence, polluted or clogged water, fires, slides and gases in OSMRE's inventory
    1 0.9%
Named features on the maps17 named · from the USGS compilation
Name on map Feature
Blair Mine Open Pit Mine
Blair Mine Open Pit Mine
Bruster Mine Open Pit Mine
Hubbard Mine Open Pit Mine
Hubbard Mine Open Pit Mine
Kellogg Mine Open Pit Mine
Kellogg Mine Open Pit Mine
Kennedy Mine Open Pit Mine
Kennedy Mine Open Pit Mine
Kingston Mine Open Pit Mine
Kingston Mine Open Pit Mine
Lenoir Mine Mine
Oertel Mine Open Pit Mine
Oertel Mine Open Pit Mine
Oertel Mine Open Pit Mine
Slezak Mine Open Pit Mine
Slezic Mine Open Pit Mine

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 problems11 on inventory
Problem area Problem Status
Birch Creek Mines P2 Portals Reclamation Completed
Birch Creek Mines P3 Spoil Area Reclamation Completed
Blair Mine P3 Gobs In Reclamation
Blair Mine P3 Spoil Area In Reclamation
Conrad West P2 Dangerous Piles & Embankments Reclamation Completed
Conrad West P2 Dangerous Piles & Embankments Reclamation Completed
Conrad West P2 Hazardous Equip & Facilities Reclamation Completed
Conrad West P2 Portals Reclamation Completed
Conrad West P2 Vertical Openings Reclamation Completed
Conrad West P2 Vertical Openings Reclamation Completed
Witt - Thorn P2 Subsidence 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 Abandoned7 on register
  1. Bokma Pit
    Surface metal/non-metal · Rocky Mountain Ready Mix · MSHA ID 2400831
    Abandoned
  2. Conrad Sand & Gravel Redi-Mix Inc
    Surface metal/non-metal · Conrad Sand & Gravel Redi-Mix Inc · MSHA ID 2401306
    Abandoned
  3. Kingsbury Colony
    Surface metal/non-metal · Kingsbury Colony · MSHA ID 2402523
    Abandoned
  4. Mc Intyre Portable Crusher No 2
    Surface metal/non-metal · Mc Intyre Construction Company · MSHA ID 2401471
    Abandoned
  5. PORTABLE SCREEN PLANT
    Surface metal/non-metal · Pondera County · MSHA ID 2401961
    Abandoned
  6. Salois Construction Portable Crusher
    Surface metal/non-metal · Salois Construction · MSHA ID 2402673
    Abandoned
  7. Stokes Excavation Inc.
    Surface metal/non-metal · Stokes Excavation Inc. · MSHA ID 2402310
    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
Gravel Pit 40
Gravel Pit 38
Open Pit Mine 17
Prospect Pit 4
P2 Dangerous Piles & Embankments 2
P2 Portals 2
P2 Vertical Openings 2
P3 Spoil Area 2
Adit 1
P2 Hazardous Equip & Facilities 1
Mine 1
P2 Subsidence 1
P3 Gobs 1
Other counties in MontanaAll 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.