The Cave Doctor

Nothing good happens fast in a cave. Those popcorn-encrusted stalactites that hang like sparkling icicles from the ceiling? They can grow about a centimeter every century, meaning a 10-centimeter specimen was just getting started around the time of the Norman Conquest. Humans, however, have a knack for undoing nature’s labor in an instant.

Visitors to the spectacular chambers of Carlsbad Caverns National Park in southern New Mexico have snapped off formations to bring home as souvenirs. They’ve thrown rocks, swung hammers and toppled the fragile creations. Decades ago, even park rangers broke formations by banging out melodies on stalactites in the Music Room. The once-pristine caves are now scarred by more than 100 years of visitation.

[FALL 2025] Cave Doctor - breakage

Stalactites grow incredibly slowly — only about a centimeter per century. Acts of vandalism can destroy thousands of years of a formation’s progress. 

PHOTO BY MICHAEL MANSUR

“It’s so sad. In such a simple motion — a baseball bat, your hand — you destroy what takes nature thousands of years to create,” said Michael Mansur, a retiree in New Mexico and the founder of the Cave Formation Repair Project. “It’s like people wanting to cut down trees just to watch them fall.”

Mansur, a compact, white-haired former mechanical technician at Intel, has been hooked on caves since his father took him into one in southwestern Vermont when he was 14 years old. Soon he was bagging groceries to save up for his first hard hat — a bright-blue aluminum one with a carbide lamp. He joined “grottos,” or caving clubs, in Vermont and New York, and learned how to map caves.

In 1986, Mansur flew to New Mexico to attend a weeklong Carlsbad Caverns restoration field camp. He and other participants spent days underground scooping garbage from cave pools with spoons attached to broomsticks. Sometimes he dangled from ropes to collect coins, batteries and other objects from cave ledges. Mansur returned for these field camps every year to help clean the caves. He moved to New Mexico, for the caves, in 1993.

At the request of cave specialists with the U.S. Forest Service, he attempted his first repair of a broken cave formation in 2018, at Black Cave in New Mexico’s Lincoln National Forest. It was a 2-foot-tall stalagmite, 10 inches in diameter, right next to the main trail. Mansur cleaned the surfaces, drilled a hole in both ends to insert a stainless-steel pin, and used a bio-neutral epoxy to glue the pieces together. Thrilled to make a formation whole again, Mansur started the Cave Formation Repair Project, a formal volunteer group.

Soon Mansur was working in caves in national forests and on Bureau of Land Management land. In 2019, he was asked to work at Carlsbad Caverns, one of America’s premier show caves and home to the Big Room, which is the largest cave chamber in the country. Park staff have documented more than 65,000 broken formations in the caverns.

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Michael Mansur has been repairing broken cave formations on public lands since 2018.

PHOTO BY CYNTHIA LACOE-MANIACI

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Mansur prepares the stalactijack max, a MacGyvered piece of cave repair equipment, in Carlsbad Caverns National Park.

PHOTO BY TODD ROBERTS

“Caves are more than just holes in the ground,” said Hunter Klein, the park’s physical science technician, who has worked on cave repairs with Mansur for more than five years both at Carlsbad Caverns and on Forest Service land. “Having those formations present and abundant for our visitors makes the wonder even greater.”

The group can only repair pieces they can find, and they only fix formations broken by humans. (Cave features falling naturally is a relatively rare occurrence.) “It’s like a crime scene,” Mansur said. “You’re like a detective trying to figure out not so much who did it, but what happened.” When a repair is finished, Mansur camouflages the joint with a mortar made of drill dust or mud. “The challenge,” he said, “is to repair something so people can’t tell you’ve repaired it.”

By now Mansur has organized more than 50 repair trips to Carlsbad Caverns, where almost half a million visitors come each year to gape at the caves’ beauty. Klein said Mansur’s cool head and multifaceted skills — he’s also a woodworker and a competitive weightlifter — make him well suited for the work.

“He’s like the best combination of an engineer and a surgeon,” Klein said. “He has the precision of a surgeon to do this without causing greater damage to the cave.”

Klein said Mansur’s care with these repairs helps conserve fragile cave environments. Volunteers wear medical gloves and eat over plastic bags, lest crumbs introduce alien nutrients into a low-energy ecosystem. Mansur’s use of hollow stainless-steel tubes to hold together formations that have an active internal drip even allows the features to continue growing.

“The cave can heal itself over time,” Klein said. “It’s not just gluing hanging things up for aesthetics.”

No two repairs are the same, and many demand new tools or techniques to be completed in the least invasive way. Stalagmites, which grow upward from the cave floor, are relatively easy to repair because gravity helps the epoxy cure. But how to repair a stalactite, hanging from the ceiling? For that, the mechanically minded Mansur drew inspiration from his shower curtain rod and devised a tool he calls the “stalactijack,” made from PVC pipe, a stainless-steel bolt and a galvanized spring that adds gentle pressure from below until the epoxy sets.

When a stalactite piece was too heavy for volunteers to safely hold aloft, the “speleocrane” was born — a PVC ladder equipped with a pulley and a rock climber’s ascender that can hoist a 75-pound formation high in the air. Other repairs led to the creation of the speleosplint, the speleotray, the speleocup and the speleoclaw, made from a hair clip. The speleoclamp braces formations horizontally, and the speleorake helps Mansur and other volunteers go “speleofishing” for broken stalactites submerged in cave pools. By now, Mansur can confidently repair formations 20 feet off the ground and weighing over 55 pounds. (He weighs the pieces with a fish scale.)

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“You have to have a general curiosity and a willingness to fix things at all costs,” Mansur said. “Like MacGyver, you just have to make the right combination of stuff. We don’t so much use chewing gum like he did, but we have ways to support things with rubber bands.”

Unlike other skilled craftsmen who may guard their techniques, Mansur shares them freely in his book, “The Cave Formation Repair Project: Restoring the Beauty of America’s Great Caves,” which is in its third edition. In it, he highlights his own tools and those inspired by others. One volunteer thought to attach an electric palm sander to the outside of a bucket of water so that broken formations could be placed inside and cleaned of mud and algae ultrasonically, without damaging fragile crystals. Another developed a technique called photo-image matching whereby broken stalactites are organized and photographed to scale to help volunteers locate their corresponding bases on the cave ceiling. Another participant suggested using a butane torch to accelerate the curing process on delicate formations such as so-called soda straws.

Mansur invites anyone to join his trips, young and old, cavers and non-cavers alike — no experience is required. Every trip fills up within a couple of weeks of announcement. Klein has noticed the volunteers share some common traits. “The people who are drawn to Mike’s work tend to be meticulous but also have a creative side to them,” Klein said. “It’s kind of like art, or a really advanced puzzle.”

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Over the past seven years, Mansur and hundreds of these volunteers have spent more than 6,000 collective hours repairing over 1,300 individual stalactites, stalagmites and other cave formations in six states, including almost 500 in Carlsbad Caverns alone. Satellite repair groups have formed in Texas, Colorado, Arizona and Utah, and cavers are applying Mansur’s knowledge in Mexico, Australia, Slovenia, the United Kingdom and China.

Klein said it helps that Mansur is an encouraging leader devoted to the work. “He’s so enthusiastic for this project, it’s hard to not get a little contagion of that for yourself,” Klein said.

Mansur is aware that the work of repairing caves will never be finished. At 71, with knees and hips that have required their own medical repairs, he also knows he can’t go on forever. It’s why he’ll spread the word to anyone who will listen.

“I’m just glad I was able to show so many people that this exists,” he said, “that this restoration is possible, before I can’t do it anymore.”