June 17, 2009
Contact: Don Drysdale
SACRAMENTO – State and federal officials are in the process of sealing a hazardous, abandoned gold mine near Mammoth Lakes to protect public safety and wildlife. The site is adjacent to the Coldwater Campground in the Inyo National Forest in Mono County.
“This is one of several projects we are working on in conjunction with the U.S. Forest Service to ensure the safety of visitors,” said Dennis O’Bryant, chief of the Office of Mine Reclamation (OMR), part of the California Department of Conservation. “This is a heavily visited site with two adits (tunnels with one opening) that tend to attract the curious. These abandoned mines are dangerous; our motto is `stay out, stay alive.’ ”
The Mammoth Consolidated Mine and Mill is a 1920s-era gold mine that has become an interpretive center. It includes an assay building, bunk houses, cookhouse and superintendent’s house as well as the mine, which has two levels connected by a shaft. There are 500 feet of mine workings on the lower level and an unknown amount of mine workings on the second level.
The adits were gated in the 1980s but have been repeatedly vandalized. The gate on the lower adit is still in place and functioning, but the gate on the upper adit is in need of complete replacement. An OMR contractor is installing a gate designed to allow bats to enter and leave the adit while keeping people out.
“The Forest Service is concerned for the health and safety for members of the public who visit the Coldwater Campground, nearby wilderness trail head, and the interpretative mine site,” said Lynn Oliver, Minerals and Geology Program Manager of the Inyo National Forest. “The Forest Service is very appreciative for the efforts of the Office of Mine Reclamation in assisting with this important closure.”
During the summer months, hundreds of people are in the vicinity of the interpretive site daily, enjoying outdoor recreation. Coldwater Campground has 75 campsites and is usually full in peak season.
“Unfortunately -- despite the presence of signs, fences or even gates -- some people feel compelled to enter these old mines, unaware of how dangerous they can be,” said Cy Oggins, manager of OMR’s Abandoned Mine Lands Unit (AMLU). “People are injured and sometimes killed in old mines each year.”
In California, 42 incidents at abandoned mines involving 13 deaths, 32 injuries or near-misses, and 13 pet or other animal rescues have been reported since 2000. The state has about 1,400 active and idle mines and AMLU estimates there are 47,000 abandoned mines in the state.
AMLU began funding abandoned mine remediation projects on California’s public lands in 2002 and has now remediated more than 580 hazardous mine features. Methods used include: bat-compatible gates, cupolas, and culverts; polyurethane foam (PUF); backfills; wire fences; capping; and removal of hazardous debris. Projects to seal old mines are ongoing or planned in several locations around the state during June,
including the Eldorado, Plumas, Stanislaus, Shasta Trinity, and Tahoe national forests.
Aside from the obvious falling hazards, dangers associated with abandoned mines include unstable walls or structures that can collapse at a touch; dark, twisting tunnels in which an explorer can become lost; disease-carrying, predatory or poisonous animals which sometimes make old mines their homes; old explosives; drums of chemicals; exposure to toxics; and poisonous gases or low oxygen levels.
There is no comprehensive database that gives the precise location of most of California’s abandoned mines or their underground workings. Many operated before the advent of any regulatory or reporting authority, or even statehood itself. Each mine may have multiple man-made “features,” such as shafts, tunnels, machinery, facilities or piles of waste rock that can pose either a physical or environmental hazard.
AMLU encourages anyone who discovers an abandoned mine in California to call its hotline, 1-877-OLD-MINE (653-6463).