On only her second day off in 50 days of 12- to 24-hour shifts fighting western forest fires, Dorothy Hays went dancing.

She and hundreds of others battling this summer's record-setting fires are having the time and challenge of their lives.But for some, fatigue is setting in. The duration of these giant blazes, fueled by drought-dried timber and erratic wind, has begun to take its toll on those cutting and digging on the front lines.

"We just don't have enough bodies anymore. We're spread so thin," U.S. Forest Service spokesman Bob McHugh said Saturday.

Firefighters work at least 12- to 16-hour shifts for at least 10 days straight before one day of rest and relaxation is granted. Some find themselves working double shifts.

Some end up in crews that employ "coyote tactics" - staying at the battle front for up to 36 hours straight until all food and supplies are exhausted.

"If you get tired, fatigue can be dangerous. You forget about safety," said Kirby More, who's been fighting fires since 1956. "But we hold up. Our folks are trained for this."

On Saturday, More's "hot shot" crew was heading to the top of a mountain ridge to clear a 40-foot-wide firebreak through the forest. The work had to be done by hand because the terrain was too steep for bulldozers.

"It ain't the fun, although at times it is fun. And it sure ain't the pay. I think I do it for the challenge, the excitement. It's one hell of a challenge, and sometimes you get to say `Damn, we stopped it,"' More said.

Hays, a Forest Service employee from Oregon, said flames twice forced her crew to retreat quickly. Her crew digs lines at the front of the Storm Creek fire, which on Friday threatened Cooke City, in south-central Montana just northeast of Yellowstone National Park.

She and the rest of her crew went to Red Lodge, about 40 miles away, Friday night and went dancing at a tavern. Saturday they were back on the fire.

"We were getting pretty tired, but the R&R was real good," she said. "It's real exciting being out there because you never know what's going to happen next. It's a lot of fun."

When the crew has to pull double shifts, 24 hours straight, "people start dropping like flies," said Brian Spivey.

Forest Service officials said some crews were losing people who had to return to school or jobs. That, coupled with new fires in other parts of the West, caused manpower problems. About 1,200 soldiers from Fort Lewis in Washington state were being trained to join the front lines.

Saturday morning, some 830 firefighters were in a camp outside this tiny town. They are paid at varying rates, starting at $6.38 an hour, since some are civilian contractors and others come from various federal agencies, including the Forest Service and Bureau of Land Management. Depending on their agency and pay scale, some receive overtime and hazard pay as well.

The Forest Service provides large, nourishing meals and lots of beverages.

"They feed you a lot of liquids and a lot of food," said James Begay, a Navajo firefighter from Window Rock, Ariz. "They keep you going."