January 16, 2007
SACRAMENTO -- Most of California’s potentially dangerous abandoned mines are a legacy of the gold rush. But recent vandalism at a former coal mining site in the Bay Area have prompted California State Parks and the Department of Conservation to team up to protect public safety.
"Thousands of people probably drive past Tesla every day without knowing that a thriving mining operation existed there a century ago," said Douglas Craig, head of Conservation's Office of Mine Reclamation (OMR). "Today, there is little evidence that there once was a community there, other than the mines themselves."
Named for Nikolas Tesla – whose groundbreaking work on electricity made TV and radio transmission possible -- the community was located 12 miles southeast of Livermore and five miles southwest of Tracy in Corral Hollow Canyon. According to "History of Tesla -- A California Coal Mining Town" by Dan L. Mosier, Tesla in its heyday had 1,500 residents and more than 200 structures.
A railroad survey company discovered coal in the area in 1855. By the late 1890s, Tesla had become California's largest coal-producing area, also producing sand and clay. A fire in 1905 destroyed key facilities, and six years later the mines closed. Tesla became a ghost town.
In 1998, with the buildings long gone and only grazing cattle as occupants, Tesla became part of the Carnegie State Vehicular Recreational Area, managed by California State Parks.
“People love to explore old mine sites, which is why we are so interested in preserving the mines for future tours,” said Bob Williamson, State Parks District Superintendent for the area. “Unfortunately, vandals have entered the site illegally and burned some of the wooden tunnel supports. The problem is that people are going into the site before it has been stabilized, creating a very dangerous situation.”
Earlier this year, State Parks contacted OMR, which among other things is charged with identifying, categorizing and mitigating California’s abandoned mines. OMR put up temporary emergency fencing toreduce the chances of an accident and today will permanently seal one of the most hazardous sites (a sand and clay mine, rather than a coal mine). An 8-foot by 8-foot bat gate, which keeps humans out while allowing birds and bats -- and, presumably, ghosts -- to come and go freely, will be installed.
“Our motto is `stay out, stay alive,’ ” said Cy Oggins, who heads OMR's Abandoned Mine Lands
Unit. “Each year, several Californians are injured or killed because they accidentally came across an abandoned mine or decided to go exploring in one.”
Added Williamson, “The safety of our visitors is, of course, our primary concern. At the same time, Tesla is a historically significant site we are preserving for the future.”
OMR and State Parks, along with the federal Office of Surface Mining, are developing a plan to close approximately 10 additional mine openings at Tesla in the future.
“We opted to fast-track the mine we’re closing today simply because every time we return to the site, there’s more evidence of illegal visitors putting themselves or future trespassers in danger,” Oggins explained. “Setting fire to the timbers was the clincher.”
There are thousands of abandoned mines in California, and there is no comprehensive database that gives the precise location of most of these 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.
OMR has concentrated its efforts on the physical hazards associated with abandoned mines and features. In the past decade, Abandoned Mine Lands Unit staff visited nearly 2,500 sites and inventoried more than 16,000 features. Sites that already have proven dangerous to the public and those located close to homes, roadways, or recreational areas are given top priority for remediation.
OMR has partnered with a variety of local, state and federal agencies to remediate more than 400 hazardous abandoned mining features in 22 counties in the past five years, including 257 features in the last two years. Projects have included bat-compatible closures similar to those at Tesla, fencing, PUF (polyurethane foam) closures, backfilling, and debris removal.
Anyone who encounters an abandoned mine site is asked to note the location and to call OMR’s hotline, 1-877-OLD-MINE, so the site can be investigated and ultimately remediated.