State Office of Mine Reclamation, BLM Seal Old Tuolumne County Mines

NR# 2011-08
CONTACT: Ed Wilson, Don Drysdale or Carrie Reinsimar, (916) 323-1886




SACRAMENTO – State and federal government entities recently completed the first phase of a project to close abandoned mines in Tuolumne County. The effort aims to ensure public safety and protect wildlife.

“Mining is a big part of California history, but every now and then people stumble across old mine shafts or tunnels and are injured or killed,” said Derek Chernow, Acting Director of the California Department of Conservation (DOC). “There are thousands of potentially hazardous sites around the state, and we’re trying to correct as many as we can as quickly as we can.”

A 2002 report by the DOC’s Office of Mine Reclamation (OMR) estimated that there are 47,000 abandoned mines in California. Many pre-date any regulatory or reporting authority, or statehood itself for that matter. There is no comprehensive database that gives the precise location  of mines or their underground workings. Each mine may have multiple man-made “features,” such as shafts, tunnels, machinery, facilities or waste piles that can present physical or environmental hazards.

The Bureau of Land Management identified potentially dangerous features in Tuolumne County at six sites where no active mining claims are in place. Using about $150,000 in American Recovery and Reinvestment Act funds, OMR oversaw the remediation of 23 mine features from  the beginning of 2011 until early May. Four shafts were backfilled with mine waste, a dozen mine features were sealed with expandable polyurethane foam, and seven tunnels were fitted with bat gates, which allows bats and other animals to come and go freely without human interference. Much of the work was done around the communities of Columbia and Big Oak Flat.

“Our goal is to do an additional 22 remediation projects at 10 sites in the county either this fall or next spring,” said Steve Jenkins, head of OMR’s Abandoned Mine Lands Unit. “We only have a couple of windows to work in because of the weather and bat usage compatibility. We got off to a bit of a late start this year because the rainy conditions made it so difficult to work in the foothills.”

Since 2002, OMR has partnered with a variety of local, state, and federal agencies to remediate more than 884 hazardous abandoned mine features in 28 counties. Sites that have drawn curious members of the public, and those located close to homes, roadways, or recreational areas are given top priority for remediation.

“When it comes to abandoned mines, our motto is `Stay Out, Stay Alive.’ As the unfortunate death of an expert SCUBA diver in Jamestown in April demonstrated, old quarries, shafts and tunnels can be very dangerous places,” Jenkins said. “Unfortunately, we don’t necessarily know where all of them are. As we were working on the first round of Tuolumne County sites, residents told us about a few other mines we didn’t know about.”

Anyone who encounters an abandoned mine site is asked to call 1-877-OLD-MINE so the site can be investigated and ultimately remediated.

In addition to ensuring the reclamation of land used for mining, DOC studies and maps mineral resources and geologic phenomena; regulates oil, gas and geothermal wells; and administers agricultural and open-space land conservation programs.