Colorado, abandoned mine maps
The two federal files record 11,097 underground mine openings in Colorado, shafts, adits and tunnels drawn on the historical topographic sheets, alongside 13,209 old mine sites. This page shows where they are, who holds the maps, and what to do if the ground moves.
Information only, no guarantee: read the limits at the foot of this page before you act on anything here.
This page
Every office on this page was opened and checked on Oct. 22, 2026.
The 11,097 underground mine openings in Colorado are spread across 64 counties, and the heaviest of them is Clear Creek County with 1,545. An opening on a historical sheet is a shaft, an adit or a tunnel that was drawn where the surveyor found it, so it marks a way into workings that run on underground, away from the point.
Colorado's cover is a protection program run by DRMS, not an insurance policy sold by insurers.
Everything here can be wrong. This is information, not a guarantee: the two federal files can be wrong, incomplete or out of date, the boundaries and the geocoder can be wrong, a point is a location and not a property line, and nothing on this page says that a mine is or is not under any particular property. Do not buy, sell, move, or make any decision about a home or about your safety on this alone. Ask the state mine map office named here for the maps, and have a qualified engineer look at the ground.
Start here
Every card goes to the office that holds the record. Use the category buttons to narrow the list.
State records
The Division of Reclamation, Mining and Safety document system (Laserfiche WebLink) with non confidential coal, minerals and prospecting permit files and the Historical Mining Books.
Open official site DRMS Data: electronic documents and mining activity mapState records
The program that safeguards abandoned openings (over 10,500 since 1980), abates coal mine subsidence and fights coal fires; subsidence emergency line 1-800-44MINES or 303-866-3567 on the MSPP page.
Open official site DRMS Inactive Mine Reclamation ProgramState records
The survey's hazard page on subsidence over abandoned mine workings, collapsing soils and karst, with its publications on coal mine subsidence in Boulder, Weld and other counties.
Open official site Colorado Geological Survey, Ground SubsidenceState records
A state program set up with a $3 million federal grant to pay for damage to Colorado homes from coal mine subsidence; information at 1-800-44MINES or Deb.Zack@state.co.us.
Open official site DRMS Mine Subsidence Protection Program (MSPP)Federal
The federal archive of maps of closed and abandoned mines, searchable by state, county, company and mine name; the images are sent on request through the map request form.
Open official site OSMRE National Mine Map RepositoryFederal
The federal inventory of abandoned mine land problems and the reclamation work funded against them, state by state and county by county.
Open official site OSMRE e-AMLISFederal
The national file of adits, shafts, pits and quarries digitised from the historical topographic sheets, each with the sheet name and the survey year.
Open official site USGS USMIN topographic mine featuresFederal
The USGS record of mines, prospects and occurrences with the commodity, the development status and the position of each site.
Open official site USGS Mineral Resources Data SystemThe map
To look at one address, one ZIP code or one town instead of the whole state, open the mine map hub search and enter it there: it takes a street address, a ZIP code or your browser location and lists what sits within the radius you choose.
Who keeps what
| What you need | Office or archive | What it can tell you |
|---|---|---|
| Maps of the workings themselves | DRMS Data: electronic documents and mining activity map | The mine name, the seam, the year the map was certified and whether your area is inside a mapped working |
| An open hole, a shaft or a subsidence emergency | DRMS Inactive Mine Reclamation Program | Report it to this office; call 911 first if anyone is in danger |
| The geology, the seams and the published mapping | Colorado Geological Survey, Ground Subsidence | Which seams were worked in your county and what the state has digitised |
| Cover for damage from mine subsidence | DRMS Mine Subsidence Protection Program (MSPP) | Whether your county is covered, what it costs and what a standard homeowner policy excludes |
| A map of a closed mine the state does not hold | OSMRE National Mine Map Repository | The federal archive of more than 275,000 mine maps, searched by state, county, company and mine name |
| Whether a reclamation project is on record near you | OSMRE e-AMLIS | The federal inventory of abandoned mine land problems and the work funded on them |
County by county
64 counties have a record in one of the two federal files. Ranked by underground openings first, because an opening is a way into workings that run on underground.
Town by town
30 towns with the most records inside its own boundary, of 142 towns that hold one.
| Town | Underground openings | Mapped features | Old mine sites |
|---|---|---|---|
| Black Hawk | 199 | 259 | 18 |
| Idaho Springs | 22 | 31 | 121 |
| Rico | 17 | 19 | 41 |
| Lakewood | 11 | 40 | 14 |
| Georgetown | 9 | 9 | 37 |
| Arvada | 7 | 14 | 9 |
| Erie | 7 | 11 | 3 |
| Nederland | 6 | 7 | 34 |
| Golden | 5 | 37 | 19 |
| Aspen | 5 | 6 | 23 |
| Louisville | 5 | 12 | 0 |
| Dacono | 5 | 5 | 0 |
| Breckenridge | 4 | 35 | 9 |
| Jamestown | 4 | 4 | 40 |
| Leadville | 4 | 11 | 19 |
| Ward | 4 | 4 | 23 |
| Empire | 3 | 3 | 39 |
| Trinidad | 3 | 6 | 1 |
| Frederick | 3 | 3 | 0 |
| Durango | 2 | 10 | 27 |
| Placerville | 2 | 2 | 15 |
| Minturn | 2 | 5 | 4 |
| Lafayette | 2 | 4 | 0 |
| Somerset | 2 | 2 | 0 |
| Silver Plume | 1 | 1 | 13 |
| Telluride | 1 | 2 | 8 |
| Firestone | 1 | 3 | 3 |
| Allenspark | 1 | 1 | 3 |
| Edwards | 1 | 2 | 0 |
| Morrison | 1 | 2 | 0 |
The real document
DRMS Data: electronic documents and mining activity map is the state route in Colorado. The Division of Reclamation, Mining and Safety document system (Laserfiche WebLink) with non confidential coal, minerals and prospecting permit files and the Historical Mining Books.
OSMRE National Mine Map Repository is the federal archive. It holds maps of more than 275,000 closed and abandoned mines, the images are not downloadable, and they are sent on request: search the repository by state, county, company or mine name, then ask for the sheet by its number through the map request form or at nmmr@osmre.gov.
A mine map is the only document that shows the rooms, the pillars and the depth of cover under a given piece of ground. A point in either federal file is a location, not a property line, and it says nothing about what lies under any particular house.
Emergency
If the ground has opened, if a hole is swallowing water or soil, if a wall or a floor has moved suddenly, or if anyone could fall in, call 911 first. A subsidence hole can keep opening, and the edge of it is not safe to stand on.
When nobody is in immediate danger, DRMS Inactive Mine Reclamation Program is the office to call in Colorado. The program that safeguards abandoned openings (over 10,500 since 1980), abates coal mine subsidence and fights coal fires; subsidence emergency line 1-800-44MINES or 303-866-3567 on the MSPP page.
Then tell the people who need the record of it: your insurer, your county emergency management office, and, if the hole is in a road or a right of way, the authority that maintains it. Photograph it with something in the frame for scale, write down the date and the time, and keep measuring it, because how fast it grows is what an engineer will ask about first.
Signs worth reporting before anything opens: doors and windows that stop closing, new cracks that run at an angle across a wall, a floor or a drive that dips, a sudden wet patch or a dry well, and a smell of sulphur or a warm patch of ground where snow melts first.
Cover
Colorado runs one of its own. DRMS Mine Subsidence Protection Program (MSPP) is the programme. A state program set up with a $3 million federal grant to pay for damage to Colorado homes from coal mine subsidence; information at 1-800-44MINES or Deb.Zack@state.co.us.
Colorado's cover is a protection program run by DRMS, not an insurance policy sold by insurers.
A standard homeowner policy excludes earth movement, and mine subsidence is earth movement, so cover for it is bought separately. Ask for the rate on your own address and ask what the policy pays for: the structure, the contents, the land, or only some of them.
The data
The topographic file holds 35,383 mapped mine features inside Colorado, 11,097 of them underground openings. The sheets they were drawn on were surveyed between 1938 and 2001. The commonest kinds are gravel pit, prospect pit and adit.
The mineral file holds 13,209 worked or prospected sites in Colorado, 11,091 of them named, with 8,605 sites recorded as a past producer. The commodities most often named are sand and gravel, gold and uranium.
How the counting was done: every point in both files was placed inside the Census TIGER 2024 county and place boundaries by its own coordinates, not by the county name written in the file, because that name is blank or wrong often enough to matter. A point that falls outside every boundary is counted in no county and no town.
What the counts are not: a count of mines under houses. A single opening can lead to workings that run for miles, and a working with no opening on a sheet is in no count at all. Only a mine map shows the rooms, and only the offices named above hold the maps.
Everything here can be wrong. This is information, not a guarantee: the two federal files can be wrong, incomplete or out of date, the boundaries and the geocoder can be wrong, a point is a location and not a property line, and nothing on this page says that a mine is or is not under any particular property. Do not buy, sell, move, or make any decision about a home or about your safety on this alone. Ask the state mine map office named here for the maps, and have a qualified engineer look at the ground.
Straight answers
Open only the answer you need.
Not from this page and not from either federal file. A point is a location, not a property line. The only document that shows the workings under a given piece of ground is the mine map, and in Colorado you ask DRMS Data: electronic documents and mining activity map for it.
Call 911 first if anyone could be hurt. After that DRMS Inactive Mine Reclamation Program is the office to tell.
Two federal files: the USGS Mineral Resources Data System and the USGS USMIN file of mine features digitised from the historical topographic sheets. Every point was placed inside the Census 2024 county and place boundaries by its own coordinates. For Colorado that is 35,383 mapped mine features and 13,209 old mine sites.
Not a standard policy, which excludes earth movement. Colorado runs the DRMS Mine Subsidence Protection Program (MSPP) for exactly this, and it is bought separately.
It means a surveyor drew a shaft, an adit or a tunnel mouth at that spot when the sheet was made. It is a way in. The workings it leads to can run a long way from it, and the map of those workings is a separate document held by the offices named on this page.
By underground openings first: Clear Creek with 1,545 openings and 1,805 mapped features; Gilpin with 1,505 openings and 2,027 mapped features; San Juan with 1,285 openings and 3,848 mapped features. Each county page lists the named workings inside it and carries its own map.
No. This is a public records guide. The offices it names and links are the official sources, and everything on this page can be wrong: check it with them before you act on it.
All states
Every state page carries that state's own offices, its own counties and its own numbers.