SCRATCHGRAVEL HILLS - Bouncing along in Joan Gabelman's government-issued Chevy Tahoe, we're more focused on the huge stones and roots in the steep sections of the road than on the mounds of rocks dotting the hillsides.

But those rock piles are why Gabelman is here today on a tour of some of the dozens of mine portals and other features rehabbed by the Bureau of Land Management in the Scratchgravels north of Helena.

Gabelman, a geologist for the BLM's abandoned mines program, and others who work on detecting and shutting off access to old mines, are trying to protect the public from the dangers posed by these historical remnants of another era. They're well aware of the recent accident in Arizona, in which two sisters riding an all-terrain vehicle plunged into an abandoned mine shaft.

The 13-year-old sister died, and the 10-year-old was seriously injured.

"That's not something that's unique," said Beth Ihle, a geologist with the Helena National Forest. "Those things have happened over the years."

With an estimated 8,500 mining claims on public lands alone in Montana - not counting mines on state-owned or private lands - abandoned mines pose an ongoing hazard.

"You're living in one of the most mineralized areas in the country," Gabelman said, noting that mining took place in the Big Belts, the Elkhorns and almost anywhere you can see standing in Helena, as well as throughout western Montana.

Vic Andersen, Montana's Mine Waste Cleanup Bureau chief, tells of a rancher near Winston who plowed into an abandoned mine on his four-wheeler while cruising through the sagebrush.

"He didn't go down the hole, but shot off the thing and broke his neck," Andersen said. "He healed up fine but that ranch has been in his family for three generations - he was 60 years old - and he didn't know that hole was there."

Old claims, new homes

One of Gabelman's first jobs when she joined the BLM nine years ago was to locate as many mine portals as she could in her region, which is based in Butte and generally includes all BLM lands from Helena to Dillon. One of her areas of interest was the Scratchgravel Hills because of its proximity to Helena and its mining history.

"It's named Scratchgravel because that's what the miners did - they literally scratched at the gravel to get to the gold," Gabelman said.

In the past few decades, scores of families built homes adjacent to the BLM land in the Scratchgravels, and it's become a playground for bikers and hikers, complete with an 18-hole disc golf course. It's also a popular party spots for teenagers.

Gabelman can see the houses and swing sets as she stands on some of mines they've closed or smoothed out here. She said that in recent years, the BLM has been able to reduce the hazards, while retaining the historic remnants - like the piles of rocks or contours crafted by mining practices.

But she adds quickly that doesn't mean some dangers don't still exist.

"I can confidently say I have addressed everything I know was out there," Gabelman says, standing at one of the par-4 folf holes. "That doesn't mean there's not more stuff out there because they're easy to miss. It doesn't take much vegetation to cover a feature.

"Still, I think we have a pretty good understanding of what we have out there, at least in the high-use areas."

While that may be true in the Scratchgravels, it's more difficult to ascertain how many mines are out there elsewhere. Andersen said that 10 years ago, when the state tried to find the "biggest and worst" in Montana, they came up with about 350 sites.

"But those are where problems surfaced, like water flowing through mines, or something big like the glory hole south of Helena," Andersen said. "There are literally several thousand more here, which can become a safety issue if someone goes in them. I don't think anyone has a good handle on it.

"Will we find more? I guarantee it."

One reason cited by Andersen is Montana's rising population and the dream home for many - a little cabin or house surrounded by or adjacent to public lands. Most of those 20-acre parcels in the woods became private property when they were developed as patented mining claims.

That "patented" label means someone had to work the claim in order to make it valid, whether it was just digging a few holes like in the Scratchgravels or going deep underground.

"They're great subdivision material because the patented mining claims already are cut into 20-acre parcels and don't have to go through subdivision review," Andersen said. "But we're finding more shafts as more people move into mined areas."

They can range in depth from a few feet to a few hundred feet.

Difficult to find

Kevin Taylor, owner of Great Divide Ski Area, knows just how difficult it is to find some of these abandoned mines.

Taylor said they bought some of the land for the ski area from descendants of Thomas Cruse, so they're well aware of the potential for abandoned mines. They've even capitalized on the history, naming one area "Mine Dump" and another "Surprise."

He still finds a surprise or two at times.

"In 1999 or 2000, I was marking the Wild West expansion with another fellow in real thick foliage, and we felt a rush of cold air," Taylor said. "We found a big opening - it was about 50 feet across and 800 feet deep."

With the help of the state Department of Environmental Quality, Taylor fenced off the portal. But he added that his children found a mine opening that went back 160 feet, and he gets occasional slumps in the terrain when parts of the underground network of tunnels collapses.

"We're not worried about it, though, because when we did our expansion in 1998 to 2001, we covered a lot of ground and are pretty familiar with where everything is," Taylor said. "People can rest assured when they ski here that the old mines don't pose a hazard."

Ihle, the Helena National Forest geologist, had a similar experience in the Big Belts after the Cave Gulch fire in 2000.

"It burned away the foliage and there were the holes," Ihle said. "We warn the public to be aware and stay on the roads and trails - it's my pitch for travel planning. They go putting around on the ATV and you never know what you'll find. There are inherent dangers in the forest."

She adds that earlier this year, a hole opened up on Magpie Road that can be attributed to an abandoned mine.

Owner's responsibility

Typically, if an abandoned mine presents an "attractive nuisance" - legalese for something known to draw people to a dangerous location - on federal or state land, the agency in charge of that property might put a grate across the opening, fill the portal with expanding insulation, or if the hole is too big, they might fence off an area.

Congress currently is trying to pass legislation to charge royalties for mining on federal lands, and using that money to fund the cleanup. In Montana alone, the state has spent more than $26 million dealing with abandoned mines, and closing the 350 priority mines could cost up to $92 million more.

During each of the past five years, the BLM has spent anywhere from $80,000 to $100,000 on these closures, Gabelman said.

The Helena National Forest typically allocates anywhere from $25,000 to $70,000 annually for closures on public lands. Ihle said they hope to deal with about half dozen abandoned mines in the newly acquired Spring Hill mining claim near Mount Helena.

Andersen notes that if an abandoned mine is found on private property, the state encourages landowners to fix the problem themselves.

"We have people who buy this stuff (patented mining claims) and they get a discount on it because it includes an old mine shaft. Then they want us to fix it for them and do it by tomorrow," Andersen said. "But the landowner is responsible for it."

He adds that due to the paperwork required for the state or federal agencies to close a mine - they need to survey for four seasons to see what kinds of critters use it and ascertain if it has any cultural significance - it's a lot easier and cheaper for private landowners to fix their own problems.

"The amount of time and money that we have to put into those mine openings can easily run $2,000 to $3,000 to get the full cultural resource stuff done on it," Andersen said. "A private party can hire a dump truck and backhoe, and get it filled for $500. We have to deal with wildlife issues and cultural issues, so we stopped doing the program years ago."

Reporter Eve Byron: 440-4076 or eve.byron@helenair.com.