By Steven K. Paulson, AP

DENVER — They have popular names like Dome Rock, Yosemite, Rocky Mountain National Park and Joshua Tree, and they all have one problem in common that seasoned rock climbers call a “ticking time-bomb” — aging climbing anchors.

The anchors, drilled and pounded into the sides of mountains, are rusting and starting to fail, and some climbers and parks are trying to replace them. Funds, however, are sparse.

Some of the anchors are made of iron and were installed in the 1960s. Others hide dangerous secrets — they are bolted in rocks that have loosened because of freezing and thawing, and there are bolts that look new on the outside, but have rotten cores.

Some bolts are so bad climbers can pull them out with their fingers.

Experienced climbers often keep logs of dangerous or failing equipment and share them with other climbers, but the information is often not available to other climbers.

Bernadette Regan, a seasoned climbing ranger at Joshua Tree National Park, about 140 miles east of Los Angeles, fell last year when a bolt broke off while she was rappelling down a popular route called “Solid Gold,” one of the park’s more popular routes.

Her life was saved because she didn’t trust the bolt and had a backup rope that kept her from plunging 150 feet to the ground.

“I was testing it, and jumped on a bolt and it broke,” she said. The bolt was replaced a week later.

Park officials held a “bolting blitz” last month that brought in master bolters from around the U.S. to do some concentrated re-bolting on ancient anchors. They replaced 62 bolts, some of them more than 30 years old.

Regan said experienced climbers are worried because the sport has drawn more interest in recent years.

She said interest soared this year after Kevin Jorgeson and Tommy Caldwell spent 19 days scaling the 3,000-foot sheer granite face of the Dawn Wall of El Capitan wall in Yosemite National Park, long considered one of the world’s most difficult climbs.

Chris Weidner, who is on the board of the Boulder Climbing Community in Colorado, said the anchors are “ticking time-bombs.”

He said it has taken years for the climbing community to band together to fix the problems because experienced climbers are a close-knit community and they don’t rely on old equipment to keep them safe.

He said thousands of climbing routes from the East Coast to the West Coast need to be fixed for new enthusiasts.

“It’s scary when you look at bolts that are corroded,” he said.

Weidner said one of his favorite routes in Rocky National Park, called “the Diamond” because of its massive diamond shape, requires climbers to climb nearly 1,000 feet vertically on ropes.

He said the mountain is dotted with rotting equipment left behind by other climbers.

He said most climbers can’t stop and spend hours drilling into granite to replace the bad equipment they find, and they climb other routes or use equipment that can be easily hammered or stuffed into a crag and removed as the climbers scale their way up.

Weidner said it will take a concerted effort to make the sport safer, and the group is asking for donations to buy the equipment.

“So far, deaths are few and far between,” said Brady Robinson, who now leads a campaign called the Access Fund dedicated to replacing the equipment.

He said every climber, no matter how experienced, falls once in a while and people are putting their lives on the line when they hook their ropes to the equipment.