The nation's wildfire control center on Saturday asked the Army to provide a battalion of infantry troops to help suppress fires in the Western United States, where nearly 13,000 firefighters are already on the lines.

The Boise Interagency Fire Center requested the military assistance to provide relief for civilian firefighters - some of whom have been on fire lines for more than two weeks - and to release firefighters to build new lines and deal with more complex situations, said spokesman Arnold Hartigan.The fire center has sent 18 instructors to Fort Lewis, Wash., to train 600 soldiers of the 1st Brigade Combat Team of the 9th Infantry Division Motorized on fighting wildfires.

After training on Sunday and Monday, the troops will be deployed in Yellowstone National Park.

Outside the park in the Bighorn National Forest, a five-man team launched an investigation into a helicopter crash west of the 6,500-acre Lost fire that killed one and injured three. The 750 people working the fire hoped for a second day of relatively calm westerly wind that on Friday supported efforts to protect a ranch and a group of summer homes.

The man killed in the helicopter crash, which occurred in rugged terrain near a fire camp, was Merrin D. Rodgers, a communications technician with the Bureau of Land Management in Lander, Wyo.

The pilot, Doug Zink, was hospitalized in Sheridan, Wyo., in stable condition. Tim Sheehan of Denver, a crew member, was hospitalized for observation but Ed Lander, of Buffalo, Wyo., came through the crash with only minor injuries.

In Montana, south of Helena, the devastating Warm Springs Creek fire in the Elkhorn Mountains cooled Friday night after dramatic runs earlier in the week, Dave Turner, fire information officer, said Saturday.

"It looks pretty good here; we had a real cool night," he said. "There was very little growth in the fire. There was very little wind."