MSHA Highlights Perimeter Controls and Hazard Reporting at Abandoned Mines
The U.S. has approximately 17,000 abandoned underground mines and 56,000 abandoned surface mines.
- By Danielle Naidu
- Sep 08, 2026
Unsecured mine openings, missing warning signs and exposed mine features should be reported to the property owner or appropriate land-management authority, according to an MSHA safety alert.
The alert identifies fencing, warning signs, posted restrictions, closures and sealed structures as measures used to restrict access to abandoned and inactive mines. MSHA advised against entering fenced or posted areas and recommended complying with all closures and warning signs.
Hazards may be reported to a Bureau of Land Management office or state Abandoned Mine Lands program. Reports may also be directed to the owner of the affected property.
Abandoned mine sites may contain vertical shafts, unstable ground and highwalls. Other hazards include oxygen-deficient or toxic air, flooded workings and old explosives. Decaying timbers, loose rock and sudden ground subsidence can create additional risks.
MSHA advised visitors to remain on marked trails in parks and on public lands. Entering sealed or posted mine structures constitutes trespassing.
The agency also warned against swimming or diving in quarries and pit lakes because of depth, entanglement and cold-water shock. Urban exploration, drone flights and rope descents into mines should also be avoided because recreational equipment does not protect against toxic air, collapses or hidden shafts.
Additional information is available in the MSHA abandoned mines safety alert.
About the Author
Danielle Naidu is assistant editor for Security Today, Campus Security Today, Occupational Health & Safety and Environmental Protection Online.