WHITEHALL — Sixty-five years ago, the Civilian Conservation Corps snaked electrical wire through Lewis and Clark Caverns to illuminate magnificent limestone formations and narrow footpaths in a Montana mountainside's pitch-black hole.
The lamps enabled visitors to view limestone columns, cathedrallike spires and formations named for the things they resemble: popcorn, bacon and soda straws. Today, the annual 55,000 visitors taking two-mile, guided cave tours still rely on those Depression-era lights.
Not for long, though.
Designers are at work on an electrical system that accounts for most of an $800,000 improvement project at Lewis and Clark Caverns State Park. Preparations include the expertise of a cave cartographer from Texas and a lighting designer for the Smithsonian Institution. Officials expect rewiring to start this fall and continue into the spring.
"We want to take advantage of the technology that has developed since the 1940s," said Tom Reilly, assistant administrator of the Montana Parks Division.
The project presents some extraordinary challenges besides the tight spaces and other constraints of an underground environment.
Because oil from human hands harms limestone formations, the electrical workers must wear gloves. Soldering or other work that produces fumes may not take place in the caves, and the lighting project must take into account the delicate Western big-eared bat, a cave inhabitant.
The caverns' remoteness in the mountains of southwestern Montana presents some logistical hurdles as well.
"We are at the end of power lines and phone lines," said Lynette Kemp, park manager. "We don't have the best of utilities up here."
The park in the London Hills is 18 miles from the mining town of Whitehall and near the Jefferson River, which Meriwether Lewis and William Clark traveled with their Corps of Discovery in 1805.
Although there is no evidence the explorers ever saw the caves 1,400 feet above the river, they were named Lewis and Clark Caverns by President Theodore Roosevelt, who designated the place a national monument in 1908. The government provided no funding, however, and in 1937 the site was dedicated as Montana's first state park.
"You feel like you're in another world," Carol Liljedahl of Livingston said after touring the caverns this month with relatives from California. "You think of castles. There were places where it looked like an underground city. It was surreal."
Less heat, better concealed
The old lighting that illuminates features such as the Swiss Village, the Cathedral Room and the Atlas Column does not meet electrical codes and has seen only minor adjustments over the years. The new system will produce less heat, which damages limestone in the 50-degree caverns, Kemp said. The lighting's cast will be more effective, and wiring will be better concealed, she said.
Cartographer Bob Richards of Sugar Land, Texas, was at Lewis and Clark Caverns this spring, first to collect survey data and later to produce detailed drawings, bending and crouching as he worked by the light of a headlamp.
Richards, whose cave cartography includes work in Mexico and Bermuda as well as the United States, will use a computer program to put the maps in final form. They will cover about two miles of Lewis and Clark Caverns.
Tailored to conditions
Lighting for the caverns must be tailored to their conditions, but some information for the project can be drawn from the relatively recent lighting of Kartchner Caverns in Arizona, Kemp said. Arizona State Parks opened part of the caverns to the public in 1999, and more in 2003.
Illumination drew on the expertise of Frank Florentine, who has designed lighting for the Smithsonian's National Air and Space Museum. Florentine is working on the Lewis and Clark Caverns project.
A new backup power generator will be installed for use when storms knock out the main electrical service. That happens once or twice a year, Kemp said. The backup now consists of a battery-operated system and employees with flashlights to help people leave the caves.
Park officials hope the lighting project will be complete next spring, but that is uncertain given the difficulties of cave work.