The Roaring Camp mine known as Caesar's Mine is one of several remaining in Amador County. Photo by: Jerry Budrick

California's Gold Country is a dangerous place, according to a recent federal audit of the nation's mines.

Long-departed mining companies honeycombed Amador and its neighboring counties with shafts and tunnels. In Amador County, miles of tunnels are known to exist under Jackson, Sutter Creek, Amador City and Plymouth. The shafts go down and the tunnels go sideways. Old tunnels occasionally collapse, causing sinkholes that can swallow entire living rooms. Innocent explorers can fall into abandoned mine shafts, which have been used as hiding places for the bodies of murder victims.

The existence of these residual subterranean treasure houses has never been willfully hidden from the public. Many have plaques posted nearby to show their locations to touring students of Golden State history. Most of these mines are on private property, so access is limited and often illegal.

Access is not limited on public land, such as that under the control of the Bureau of Land Management. BLM California manages 15.2 million acres of public lands, nearly 15 percent of the state's land area. The bureau also administers 47 million acres of subsurface mineral estate underlying federal surface land. Estimates of the number of abandoned mines in California range as high as 47,000.

A recent report from the U.S. Department of the Interior chastised the Bureau of Land Management for its lack of action in protecting the public from abandoned mines on public land. The Associated Press called the report "a scathing audit."

According to the report, the Interior Department's inspector general found dangerous levels of arsenic, lead and mercury, along with gaping cavities, at dilapidated hard-rock mining sites easily accessible to visitors and residents. These sites are not exclusively in California. Many are in the neighboring states of Nevada and Arizona.

The thrust of the Interior Department's report is that the BLM should be making a greater effort at protecting citizens against the dangers posed by the many abandoned mines. At the very least, the report suggests, the BLM should be erecting fences and posting warning signs.

The enormity of the task of cleaning up the abandoned mines boggles the imagination for some. Environmentalists have estimated cleanup costs as high as $72 billion, a figure that has spawned considerable interest from groups keen on working toward remediation of the destruction caused by the mining industry.

Amador County was the second most productive gold-mining county in California, trailing only Nevada County in total production in the hundred-or-so years of gold mining.

Close to home, Sutter Creek and Jackson both take advantage of the gold mines as major tourist attractions, although the official tours are closely monitored for the safety of visitors. Sutter Gold Mine, between Amador City and Sutter Creek, requires hard hats on all who venture into its glory hole. The Kennedy Mine in Jackson keeps its clientele safely on the surface and its hazards behind sturdy fences.

Two recent attempts at creating walking trails through areas formerly used as depositories for the detritus of deep, hard-rock mining have been subjected to the scrutiny of the California Department of Toxic Substance Control.

The city of Sutter Creek had planned to reopen the site of the Central Eureka Mine in July, hoping to add its fascinating history and scenery to the town's amenities. The plan has been delayed by the DTSC, which insisted that further testing be conducted and a Remedial Action Workplan be submitted and work completed before the area can be opened to the public.

"If that sampling can be done this month, the results should be available by the end of September," said Sutter Creek Assistant City Manager Sean Rabe. "The Remedial Action Workplan could then be completed by the end of the year, if not sooner."

In Jackson, the 155-acre parcel of land known as Oro de Amador, donated to the city a few years ago, is also in the midst of DTSC-required testing. "The results are due soon on Oro de Amador," said Jackson City Manager Mike Daly.

In both cases, the suspicion is contamination in the soil. In Sutter Creek, it is arsenic, while in Jackson, the likelihood is both arsenic and cyanide.

Both cities anticipate the need to bring in certified clean soil and/or gravel to place on top of hazardous soils as protection against hazardous dust rising from the trails through the historic mine sites.

"We may need to bring in fresh dirt or put in Astroturf," Daly said.

The city of Sutter Creek received a letter in July from DTSC certifying that the remedy is complete after 14 years of protective cleanup efforts and interim testing at Mesa De Oro, a subdivision built on tailings from the Central Eureka Mine. The protective measures employed on and below Mesa De Oro were similar to those expected to be used on the Central Eureka and Oro de Amador trail systems.

A side note to the fear of rising arsenic is its specific gravity. Specific gravity is a measurement of the weight of a substance relative to the identical volume of pure water. The weight of water on the specific gravity scale is 1. Granite and quartz, common rocks found in the area, have specific gravities of 2.6. Arsenic has a specific gravity of 5.67. Gold is 19.3 times as heavy as water.

Also of note is that families can reduce their exposure to cyanide by not breathing in tobacco smoke, which is the most common source of cyanide exposure for the general population.