Plenty of vacancies at the bat motel

THERE’S HOLES IN THESE HILLS, AND HALF A DOZEN guys have gathered out here, on a dry rise about 10 miles from the nearest paved road, to squint into a few. The ground glimmers with bits of quartz. We step amid lengths of splintered old lumber, and I hope for the sound of fluttering furry wings.

“This one goes way down; we don’t know how far,” says Ted Weasma, a geologist for the National Park Service, peering into one murky declivity. “None of the old maps tell us. This is where the head frame sat. This is where the hoist frame was set up.”

Douglas Craig, manager of the state Conservation Department’s Abandoned Mine Lands Unit, stands a few yards beyond, by another one.

“The first time I came to this site, it took my breath away,” he says. “You can just picture a motorcycle falling in here.”

Meanwhile, consultant Ed Winchester, hired by the state, crawls atop yet another hole, just a few feet away, laying bars to make a steel grid across the opening. He wears a welder’s mask, a grimy green shirt, pants drenched in desert dust. His torch spits white fire.

“Another quarter-inch,” says Winchester, and a co-worker nudges the bar.

For most of the 20th century, these holes were gold mines. From the Mojave to the Sierra foothills, state officials estimate today that 47,000 old mines lie on California’s public and private lands: a great, scattered testament to our state’s history but also a grave danger to hikers, bikers, off-roaders and curious kids. In the last three years, at least four Californians have died in old mines. Last month, a 21-year-old motorcyclist fell into an abandoned shaft near Red Mountain in northwest San Bernardino County and fell more than 500 feet to his death.

Some of these old mines are 20 feet deep; some are 200. Some run straight down; some slant at a 45-degree angle; some lie half-collapsed. Some run horizontally into the base of a hillside for 900 feet.

Blocking these off may seem a no-brainer, especially in spots like this one, lying so close to a public dirt road. But it’s not as easy as it seems.

For one thing, half of these sites lie on private property. For another, we’ve been a little slow on the uptake. Craig’s Abandoned Mine Lands Unit has been up and running for only a few years, and not until 2003 did legislators resolve to pay for their good intentions by passing a law that assesses current mining companies to help pay for making old mines safe. But even when you combine remediation efforts with inventory development work, spending on the issue remains well south of $1 million a year. And the National Park Service properties in California have even less.

But never mind the money. The most vexing part of this picture is how these fatal hazards have evolved into crucial habitats.

While human hordes have been plunging shovels and backhoes into North America’s hills and canyons for the last century, millions of bats have been steadily chased out of native caves and forests. Their Plan B is the mines we’ve left behind.

Experts say this dusty hillock, dotted with three-dozen dark holes, broken-down wooden structures and old gravel piles, is home to at least four bat species. We can’t see, hear or smell them at the moment, but they’re the real reason for that metal grid Winchester is welding.

Officially, it’s a bat cupola, designed to cover a hole with a straight-down drop, carrying a price tag of about $10,000. A few hundred yards downslope, at the foot of this hill, workers last month blocked a horizontal walk-in passage with a less-elaborate bat gate (cost: about $5,000). Somehow, somebody has calculated that most bars need to be set 5 3/4 inches apart to give bats the room they need, yet still keep people out.

At sites where biologists see no evidence of bats, workers can simply move dirt or stop up holes with big polyurethane plugs, both of which are much cheaper than cupolas or gates.

But bats are all over the place. Bat Conservation International, a 20-year-old nonprofit organization based in Austin, Texas, estimates that more than half of North America’s 46 bat species, including many threatened species, “depend on abandoned mines at one time or another during the year.”

Before the organization took up the cause of mine-roosting bats in 1993, conservation specialist Faith Watkins says millions of bats were probably buried inadvertently during old-school, dump-some-dirt mine closures. (And if you think a future with fewer bats might not be so bad, bear in mind what bats eat: night-flying insects, by the billions.)

In the last two years, Craig says, his department has cleaned up about 150 “features” at about 50 mines in 12 counties, most of them on land managed by the National Park Service, the U.S. Forest Service or the U.S. Bureau of Land Management, with about a quarter of them requiring bat-protection measures. (A “feature” can be anything from a hole in the ground to a leftover wooden structure.) Now that the agency has a steady revenue source, the year ahead is likely to set a record for mine remediation.

But it’s never going to be easy, chasing down California history, hole by hole, all the while balancing human safety, historic preservation and bat conservation. Not too long ago, Craig’s office calculated that with 10 staffers on the job, it would take 26 years just to come up with a good inventory of California’s old mines, never mind actually plugging the holes.

But Craig’s staff is only three, and they split their time between inventory and hole-plugging. You can do the math if you like, but out here in the hills, the bottom line is clear: Sometimes there’s nothing more complex than a hole in the ground.

To e-mail Christopher Reynolds or to read his previous Wild West columns, go to latimes.com/chrisreynolds.