Hazards and Safety

pump jack and large tank
Oil and Gas Extraction Equipment, Big South Fork National River and Recreation Area, Kentucky.

NPS photo

Stay Out and Stay Alive!
Occasionally, adventurous people enter abandoned mines and wells. Some are injured or do not make it out because they fell victim to one or more of the many hazards associated with abandoned mineral sites.

Water Hazards
Many abandoned mines become flooded. The most common cause of death in abandoned mines nationally is drowning in water-filled quarries and pits due to the presence of rock ledges, old machinery, and other hazards that may be hidden beneath the water's surface. The water can be deceptively deep and dangerously cold;and steep, unstable, slippery walls make exiting these features extremely difficult. In underground mines, shallow water can conceal sharp objects, drop-offs, and other hazards.
mine opening and wooden structure
Unstable adits and structures are common hazards at abandoned mines. Talc mine, Death Valley National Monument, California.

NPS photo

Deadly Gases and Oxygen Deficiency
Lethal concentrations of carbon monoxide, carbon dioxide, methane, hydrogen sulfide, and other gasses can accumulate in underground passages. Pockets of still air with extremely low oxygen levels can be encountered. By the time persons feel ill, they are no longer able to react.

Cave-Ins
Mines can cave in at any time! The effects of blasting and weathering destabilize once-competent bedrock through time.

Unsafe Structures
Support timbers, ladders, cabins, pump jacks, tanks, and other related structures may seem safe but can easily crumble under a person's weight. Do not be fooled by appearances!
mine shaft with wooden supports
Unprotected shafts can be an extreme safety hazard. Two-hundred-foot deep shaft, Lake Mead National Recreation Area, Nevada.

NPS photo

Unstable Explosives
Unused or misfired explosives are deadly. Because old explosives become unstable, minimal vibrations from a touch or footfall can trigger an explosion.

Highwalls
The vertical and near-vertical edges of open pits and quarries are called "highwalls." These highwalls can be unstable and prone to collapse. Do not climb near or on highwalls.

Pits
Mud pits once used for oil and gas operations can contain hazardous materials and may be the consistency of quicksand.
gravel pit with water covering the bottom
Sand and gravel pits make up a significant portion of the abandoned mines in the NPS, Cuyahoga Valley National Recreation Area, Ohio.

NPS photo

Radioactivity
Some of the materials that were mined, such as uranium and thorium, are radioactive. Because the effects of radiation exposure are cumulative throughout a lifetime, exposure from mines can be harmful to humans, wildlife, and plants.

Designed for the Short-Term
Mines were constructed and maintained to be safe only while they were in operation. When the miners departed in search of more lucrative deposits, they often left vertical openings uncovered and removed the ventilation and water-pumping systems. Support structures, timbers, and ore pillars were removed or left to rot, leaving the mines much less stable than when they were operating. Modern laws and regulations require miners to leave properties in a safe condition, but this was not the case in past decades.
drill rig
Remnants of an oil and gas rig, Channel Islands National Park, California.

NPS photo

Mines Are Not Caves
Caves are formed naturally over thousands or even millions of years. Mines, in contrast, are developed in a comparatively short time, often in inherently unstable structures such as faults, through blasting, which fractures and destabilizes the wall and roof rocks. Most underground mines do not have natural ventilation and consequently can have lethal air traps. Even experienced cavers can die exploring mines.

Rescues
Underground mine rescues are extremely hazardous. Mine rescue teams, despite their extensive training, are at significant risk every time they enter an abandoned mine. When people decide to enter an abandoned mine, they not only risk their own life, but the lives of those who might be called to rescue them when they get lost or injured underground. The tragic and unfortunate reality is that many mine rescues turn into body recoveries.

Last updated: February 29, 2016

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