Wildfires in Colorado

A 7,100-acre wildfire burned out of control west of Boulder, Colorado, on Wednesday, threatening hundreds of homes, forcing the evacuation of thousands and pressing additional fire crews into action, authorities said.

"We do have 92 structures that have been destroyed and eight that have been damaged," said Rick Brough, a commander with the Boulder County sheriff's office, who added that flames have spread throughout the Fourmile Canyon area west of Boulder.

Colorado Gov. Bill Ritter declared a state of emergency Tuesday.

Ritter said he saw "entire hillsides" burned by the flames, along with numerous structures.

"It's not safe for people to return to their homes, because as we drove up there, you go from a place that is relatively safe, and then suddenly, you'd see a spot fire burning on the side of the road," he said.

More than 200 firefighters, from at least 35 local, regional and national agencies are working to contain the fire, according to the Boulder Office of Emergency Management.

Eight air tankers and three helicopters dropped more than 90,000 gallons of retardant on the fire Tuesday.