Authorities have questioned three teen-age boys as they investigate the cause of a 2,500-acre wildfire that has threatened homes in the foothill town.

The blaze was 35 percent contained Friday as light rain sprinkled the area and crews worked to build fire lines, but officials feared more wind could slow the fight. About 150 homes remained evacuated.

"They're making excellent progress. They're way ahead of their expectations," fire operations chief Mike Rieser said.

The boys being questioned were seen running from a ridge behind the high school when the fire started Tuesday, said Park County Sheriff Fred Wegener. Smokers often gather on the ridge.

"We're looking into the possibility that they were ditching a class at the time," Wegener said.

Winds whipped the fires across tinder-dry brush and trees to within a quarter-mile of downtown in the community of 4,400 people about 35 miles southwest of Denver.

The National Weather Service said there was a chance of mountain snowfall Friday night and Saturday, but the weather was expected to dry out again by Sunday.

In central New Mexico, firefighters contained a 300-acre fire in the Magdalena Mountains and were trying to snuff out hot spots on Friday.

In Arizona, firefighters fully contained a wildfire that charred 1,120 acres in steep terrain in the Baboquivari Wilderness, about 45 miles southwest of Tucson.

A winter drought has plagued much of the West, triggering an early start to the wildfire season.