Behind an unmarked warehouse in Red Mountain, an unincorporated community in Southern California, Sterling White drops a pebble down the hole. It bounces off the sides of the pit, the sound reverberating and then slowly fading, long before the rock hits the bottom. White, who is a resource specialist for the federal Bureau of Land Management (BLM), estimates that it’s about 300 or 400 feet deep.

These days, the old mining shaft is covered with a thick steel gate, strong enough White says that someone could drive on top of it. Not that many years ago, though, it was uncovered, a treacherous hole in the ground for anyone unlucky — or reckless — enough to go in. Red Mountain, a small town in the Mojave Desert with 130 residents, calls itself a “living ghost town,” alongside neighboring Johannesburg and Randsburg (named for the famous gold region of South Africa). The legacy of mining is everywhere in this quiet, dusty corner of California.

According to state estimates, at least 100,000 shafts, pits, tunnels, trenches, and other abandoned mining features litter the landscape of California, most of them on public lands across almost every county of the state. More than half of those sites are in the three giant counties of California’s desert southeast, including this one, San Bernadino.

Some of these old mining features are little more than a “scratch in the ground,” as White describes them. But many pose a safety threat to unsuspecting hikers, reckless thriller seekers, and animals.

In 2002, for example, two brothers asphyxiated in a mine shaft with little oxygen in Orange County; in 2009, a woman fell 100 feet when a tunnel collapsed in Kern County, and in 2015, veterinarians rescued a 1,200-pound cow that had fallen into a shaft. People have suffered carbon monoxide poisoning, gotten lost in underground tunnels, or been attacked by animals that use the mines for shelter.

According to California state estimates, between 2000 and 2021, at least 37 people died in these abandoned mines, 67 had “near misses,” and 26 domestic animals were lost.

Abandoned mines are found across the West, but California is ground zero. “California has the greatest number of people, most recreation, and most mines in those areas that people like to play,” White says. Just about every unnatural bump off the side of the road driving into Red Mountain, he points out, is a remnant of a mining operation, and the tracks of off-road vehicle and motorbikes weave across the hillsides above town. In 2004, a man tried and failed to jump across a nearby open mine shaft on his motorcycle, falling 700 feet to his death.

Given the scale of the problem, federal land managers face an uphill battle to reclaim these dangerous sites. Experts say that a lack of funding is the greatest challenge. There’s not enough money to even identify all the sites, let along clean them up.

Hardrock mining on public lands is governed by the General Mining Law of 1872, an archaic legislation that offers little by way of environmental protection or remediation requirements. Activists have long been trying to reform the law. But repeated efforts to reform it have failed, including a 2021 proposed legislation that would have created a reclamation fee for abandoned mines.

While the 2021 Bipartisan Infrastructure Law, includes significant funding to facilitate remediation of contaminated sites (Red Mountain received money last year to address the toxic arsenic that’s plagued the town’s water supply for decades), experts say it provides little new funding for physical safety issues specifically.

“I was involved in reviewing the infrastructure bill, and there’s a lot of money going to mine cleanup. But the AML [Abandoned Mines Land] world really didn’t get any money,” says Scott Ludwig, who runs the abandoned mines land program nationally for the US Forest Service, as well as the regional program in the Rocky Mountains. Yet, according to the state, 84 percent of the abandoned mines in California pose some kind of immediate threat to human safety.

Those state estimates, though, are just that — estimates. “We always make the joke that if you find one hole in the ground, you’re going to find five more,” laments Mary Rosellen, a Forest Service program manager who serves as abandoned mine lands coordinator for California.

Removing a single physical hazard is a multi-step process. First, wildlife biologists look for endangered species like desert tortoises and bats, while archaeologists work to identify culturally or historically important artifacts and scientists collect environmental data to ensure that there’s no pollution. Contaminated sites, though rarer, require a more complicated and expensive cleanup process.

Once the site is surveyed, engineers can backfill a shaft with nearby rocks, concrete, or polyurethane foam. If there are bats, tortoises, or owls, though, White says they must install wildlife-friendly steel gates or domes, which can prevent humans from getting inside but allow animals to come and go. A simple backfill costs about $800, but a gate can cost $10,000. And if any historically-significant items are found at the site, those need to be protected as well.

Unsurprisingly, costs add up.

For example, just one project outside of Adelanto, California, a popular off-roading destination not far from Red Mountain, cost well over $50,000 to remediate just 20 mine shafts.

There are likely hundreds more such shafts in the area, White says.

The Federal Surface Mining Control and Reclamation Act of 1977 (SMCRA), which imposes a cleanup fee on coal mining, has provided significant funding for some states to undertake this work. Ludwig says the Forest Service has funded reclamation projects totaling about $2 million in Wyoming using those funds. But California has no active coal mines and can’t draw on those funds.

Under California law, active gold and silver mine operators pay a small fee that can be used for cleanup. Over the last five years, though, the state has only appropriated some $800,000 from that fund, nowhere close to the tens of thousands of dollars that the state Legislative Analyst’s Office estimates is needed to pay for the cleanup of all the sites.

Rosellen says that insufficient funding doesn’t just prevent the work from getting done, but also creates staff shortages. The Forest Service has had to “wash our hands” of some regional offices within California when there’s not the money or people to do the work, she says.

“We’re wearing a billion different hats,” Rosellen says, “A lot of that is due to attrition.” The Forest Service budget, broadly, has gradually gone down every year, forcing some staff to move to different teams or leave the agency entirely, taking their knowledge and experience with them, she added.

Additionally, for the two-thirds of abandoned mines across California that are on public land, access is another major challenge.

“We have an obligation to allow people to recreate on national forests,” says Rosellen. With access, though, comes added risks. Both Ludwig and Rosellen say social media has complicated their job by drawing people to these sites, sometimes in large numbers, where fences and signs only do so much to stop them.

One way the Forest Service is dealing with this is by making some sites more difficult to access, especially by motor vehicles. “That’s been a big strategy for us to try and manage access as opposed to the site itself,” Rosellen says.

Access, in fact, is the major consideration that land managers use to determine which sites to prioritize for remediation, given budget and staff shortfalls. The most pressing sites, experts agree, aren’t necessarily the most dangerous ones but rather the most accessible, in terms of proximity to roads, towns, and recreation opportunities.

Managing access isn’t just about keeping people safe and avoiding legal liability, though. It’s also about preventing vandalism, which experts says is rampant and eating into the limited time and money agencies have to patrol these sites.

“My approach has been to put in these ‘hell for stout’ mine features,” explains White, referencing an old saying for over-engineering a project. The BLM previously relied more on fences and signs to block access, but, White says, they often served as invitation for vandals and thrill seekers. “Building structures out of the heaviest iron is going to buy you more time in the very long term,” he says.

Even so, vandals recently firebombed a mine shaft he had blocked with a steel gate. The metal held, but the historic woodwork of the shaft, which was over 100 years old, was all gone.

And, as with many things, climate disruptions are making matters worse. While less of an issue in the California desert, increasing fire activity in recent years has complicated cleanup efforts in other parts of the state and across the US West.

Wildfire damage and burned-out forest exposes dilapidated buildings, rusty equipment, open mine shafts, and old tunnels, which bring new safety risks. After a fire outside of Denver in 2017, Ludwig says, they discovered 38 new features that hadn’t been on any map.

Abandoned mines also make firefighting harder. Ludwig’s cleanup team works closely with the Forest Service’s incident command to ensure that firefighters are aware of all the risks they might stumble across—or into. “I was a firefighter years ago, and I was always terrified as hell that, working on a line some night, I was going to fall in some shaft,” he says.

Meanwhile, the growing costs of firefighting has drawn an increasing amount of the agency’s budget away from other activities. In 2017, for example, fire suppression cost the agency over $2 billion dollars, more than half the Forest Service’s annual budget.

Given the risks, the need to protect people from these dangerous sites is only becoming more urgent.

“What I can do is keep people from going into the mines and hurting themselves,” White says. “I don’t have control over the bigger issue, but I have control over the hole itself.”