"It's a nasty one. We hope the weather will cut us a break in the next couple of days," U.S. Forest Service spokesman Dave Steinke said. Winds already were calmer and the humidity higher Monday, he said.
The blaze threatened more than 1,000 houses, outbuildings and other structures in Beulah and surrounding ranching country, nestled in dry terrain in mountains about 150 miles south of Denver.
No injuries had been reported and no homes had burned.
Residents forced from their homes met for coffee and searched for news.
"Sitting around, waiting to see if your house is going to burn down is the strangest feeling," said Angie Griggs, 49. "Now we're just laughing about it because what else can you do? You can't cry."
Gov. Bill Owens declared a state of emergency for the area and put National Guard helicopters on standby.
In South Dakota, a wildfire blackened more than 3,000 acres in the Piedmont area of the Black Hills, destroying a house and a garage, authorities reported. Some 500 people were battling the blaze. The only reported injury was to a firefighter, who recovered from a heat-related condition on Sunday.
According to the National Interagency Fire Center, 11 large wildfires were burning on more than 500,000 acres in seven states Monday. The acreage burned to date is similar to the same periods last year and in 2002.