Cave Restoration

By William R. Elliott and Jonathan B. Beard | October 2, 2000
From Missouri Conservationist: Oct 2000

Visitors to Missouri caves often are spellbound by the natural beauty they find, but caves aren’t always as lovely as they could be. Many times they are missing delicate speleothems that have been destroyed or removed by previous visitors. Or, the caves may be marred by fires, digging, marking on walls, littering or the killing of cave wildlife - all of which are illegal.

Just as conservationists restore prairies, forests, glades, and wetlands, a few dedicated cavers and conservation biologists are working to restore abused caves. Much of the work in Missouri is carried out by caving groups, called "grottoes," the Missouri Caves and Karst Conservancy, the Conservation Department and other public agencies.

No one can completely repair all the damage to a cave. A broken stalactite or stalagmite that took millennia to form from dripping or flowing water may never regrow. The path the mineral-laden water took through the bedrock may now be naturally cemented, or conditions may be different than in the past.

It’s also difficult fix any darkening or inhibition of growth that may have resulted after porous rock has been contaminated by skin oils or mud. Cave restorers accept the fact that damage often occurs much more quickly than it can be fixed and that their efforts will never restore a cave to pristine condition. Even after we labor to clean spray-painted graffiti from a cave wall, the results are often unsatisfactory.

During restoration, we must be careful not to further damage cave resources. We don’t use harsh chemicals that can poison cave life, and we avoid using stiff wire brushes that might scratch the rock. We always start with gentle methods, like nylon scrub brushes and cave water, and see how successful we can be with muscle power.

Graffiti in caves goes back to prehistoric times and may be as important as a cave’s geologic features. In 1992, an enthusiastic and overzealous group of young restorers armed with wire brushes severely damaged 15,000-year-old bison paintings in a French cave.

Before restoration begins, we carefully explore the cave and document what we find with photographs. We then decide what graffiti should be removed and what should remain. Cave restorers don’t remove old pictographs, petroglyphs, signatures or anything else that might carry special historical significance.

If graffiti becomes cemented under a coating of calcite, we may leave it alone and let the calcite continue to cover it, or we may carefully grind it off. Another option, especially when bedrock is defaced, is to conceal it with color-matched mud.

Before Jolly Cave in southwestern Missouri was sealed by its owner in 1971, many visitors marked its walls and formations with soot and paint, built bonfires inside and drove away the bats. After acquiring the cave as part of Capps Creek Conservation Area, the Conservation Department reopened the cave in 1998.

The Ozark Highlands Grotto of Springfield volunteered to work at restoring Jolly Cave. They first removed a large amount of trash and have been washing away what they can of the soot and graffiti. However, they can’t remove it all because some of the sooty formations have been coated with a thin patina of sparkly, white calcite.

Hopefully these speleothems will regenerate, but that process could take hundreds of years. The cave is now gated to prevent further vandalism, but volunteer groups are allowed access to continue the restoration work.

The Ozark Highlands Grotto learned many of their restoration techniques in the 1980s when they began work on Breakdown Cave, a privately owned, severely abused cave.

The cave has become a laboratory for new methods and a classroom for training youth groups. It has become a proving ground for methods of removing muddy hand prints and graffiti. The cave also was the site where a new technique for repairing broken speleothems was developed.

One method of repairing stalactites involves drilling matching holes that are angled to each side of the break and filling the holes with epoxy. A stainless steel bolt with its head removed is threaded into one hole, and the other end of the bolt is inserted into the matching hole on the other side of the break. Often the angled bolt can be threaded so snugly into the speleothem that it is unnecessary to prop up the stalactite with a brace until the epoxy cures.

Other cave conservation tools include photo monitoring and mapping. Many cavers document caves by mapping them in detail with compass and tape surveys. Cave photography, a challenging art requiring the use of multiple flash units, can record the conditions in a cave for posterity.

Building gates on caves is a tool of last resort. We gate caves to protect endangered or fragile species or beauty that otherwise would be lost to rampant vandalism.

Recently the Conservation Department gated Little Scott Cave, which is located at Pea Ridge Conservation Area in Washington County. Cavers from three St. Louis grottoes repeatedly cleaned the cave, but the cave was abused for so many years that only a gate could prevent vandals from continuing to trash it. Responsible groups can easily obtain a caving permit for the cave by calling the Conservation Department’s East Central Regional Office in Sullivan at (573) 468-3335.

Some cave owners have filled or gated caves because they feared legal liability if someone was injured. However, we know of no successful lawsuit in the United States against a cave owner for the injury or death of a cave visitor. Missouri and many other states protect landowners from liability for injuries related to natural features like caves, unless they are used as commercial attractions.

Cave gates are now built to be as environmentally friendly and as strong as possible, using designs specified by the American Cave Conservation Association and Bat Conservation International.

The gates are typically made of heavy-duty angle iron with spacing that will not hinder the flow of air and water. The bars are spaced about 5 3/4 inches apart, and the vertical posts are placed as far apart as engineering allows to permit bats a wide flyway.

The gate is pinned into the bedrock with one-inch hardened steel rod, and reinforced concrete is sometimes used to prevent vandals from digging under the gate. The bars are reinforced with angle iron stiffeners welded inside. The lock is protected in an enclosed steel box on the inside of the gate to prevent vandals from easily attacking it with tools.

It is illegal in Missouri to tamper with any cave gate or lock. Public agencies pursue and prosecute those who illegally enter protected caves. One must obtain permission to enter private caves, and also many public caves.

Different styles of cave gates are used in different types of entrances. Maternity colonies of gray bats will not tolerate a full gate across the cave entrance. In maternity caves with a large entrance, we sometimes build a "half gate" that has an open flyway above it. A large overhang is built at the top to prevent intruders from climbing over the gate. Some of these caves are available for caving by permit during limited periods between the winter and summer bat seasons.

Managing caves for endangered bat species, such as the Indiana and the gray bat, we have to take into account seasonal bat use of particular caves. Gray bats use certain caves in the winter and different caves in the summer, while Indiana bats use certain chilly caves only in the fall and winter. They stay in forests during the summer.

Some bat caves don’t need gating, and some cave entrances can’t be gated because of their size and shape.

Good cave management also takes into account the cave’s place in the natural setting. Food, air and water inputs are not altered. During cave cleanups, we remove old woodpiles slowly over time - even if they have been placed there recently - because they may be providing food and shelter for secretive cave creatures. However, hard trash, such as cans, bottles and plastics, are removed quickly.

Pristine caves are sometimes protected by secrecy, agreements or gating. For management purposes, public agencies in Missouri inventory and classify their caves into three categories: open, restricted or closed. Many caves remain open to the public, but only if visitors use proper caving gear and methods and respect the caves.

Caves are not renewable resources, and restoring caves after they have been damaged is not a good solution. The only recourse to vandalism and damaging overuse of caves is conservation through education and protection before damage is done.

Learning about restoring caves

  • The Conservation Department and some Missouri universities offer classes in cave science and ecology.
  • Public school teachers can earn credits at summer cave classes at the Jerry Presley Conservation Education Center in Shannon County.
  • William Elliott, the Conservation Department's cave biologist is available or public lectures on caves and cave life.
  • The Missouri Caves and Karst Conservancy and other organizations assist cave owners in conserving and protecting their caves.

This Issue's Staff

Editor - Tom Cwynar
Managing Editor - Bryan Hendricks
Art Editor - Dickson Stauffer
Designer - Tracy Ritter
Artist - Dave Besenger
Artist - Mark Raithel
Photographer - Jim Rathert
Photographer - Cliff White
Staff Writer - Jim Low
Staff Writer - Joan McKee
Composition - Libby Bode Block
Circulation - Bertha Bainer