Core warning
Historic and abandoned mine sites can be lethal. Openings may be unmarked, unstable, flooded, or filled with oxygen-deficient or toxic air. Vertical shafts, rotten timber, loose rock, explosives residue, and sudden collapses are common hazards. A listing, map marker, photograph, member visit, or verification on this site is not permission to enter any underground working, surface excavation, or private land.
UndergroundMines.com provides historical and geographic reference information only. Abandoned mines may contain unstable ground, bad air, hidden shafts, explosives residue, flooding, and other lethal hazards. A listing or map marker is not permission to enter any property or underground working. This site does not authorize trespass, does not provide route finding into closed workings, and is not a substitute for landowner permission, agency regulations, or professional mine safety training.
What this site is — and is not
- Is: a reference database of documented underground mines, shafts, adits, tunnels, and related historic workings, with source citations, community verification, and privacy-aware location display.
- Is not: a trip-planning guide for underground entry, a land-access permit, a safety inspection, a rescue service, or professional engineering or legal advice.
- We do not publish techniques for bypassing gates, seals, fences, or closures, and we do not encourage trespass.
Hazards you must assume are present
- Unstable ground, collapses, and false floors over voids
- Vertical drops, winzes, and unguarded shaft collars
- Bad air (low oxygen, carbon dioxide, carbon monoxide, hydrogen sulfide, and other gases)
- Flooding, mud, and sudden water inflows
- Rotten timber, failing bulkheads, and falling rock
- Explosives residue, blasting caps, and chemical contamination
- Wildlife, abandoned equipment, and sharp debris
- Remote locations with limited cellphone coverage and long emergency response times
Conditions change. A report that a portal was open, gated, or collapsed on one date is not a current safety assessment.
Land access and permission
- Public land does not mean underground entry is allowed.
- Mines may sit on private, tribal, federal, state, county, patented, or mixed ownership lands.
- Always verify ownership, land-manager rules, seasonal closures, mining claims, and any required permits before visiting a surface site.
- Respect posted closures, gates, seals, and “no trespassing” signs.
Member reports are not safety guarantees
Verifications, visit confirmations, condition reports, photos, and trip stories are member observations. They may be incomplete, outdated, or incorrect. They are not certifications of structural stability, air quality, legal access, or safe travel.
If you choose to visit a surface site
- Stay outside sealed, gated, or unstable openings unless you have qualified mine-safety training, gas monitoring, structural assessment, and explicit permission from the controlling landowner or agency.
- Do not enter abandoned underground workings casually or for photography alone.
- Tell someone your plans, carry appropriate emergency communications, and leave if conditions are uncertain.
- Never remove historic artifacts, damage seals, or create new hazards for others.
Children and pets
Do not allow children or pets near unmarked openings, shaft collars, or unstable waste dumps. Many historic hazards are not obvious from the surface.
Emergencies
If someone is injured or trapped at a mine site, contact local emergency services immediately. Do not enter workings to attempt an untrained rescue — that often creates additional casualties.
Related pages
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Last updated: August 10, 2026