Boulder, Colo. Flames leaped from tree to tree and shot high into the air Saturday as a wildfire raged through 400 acres west of Boulder, forcing 200 families to evacuate their mountain homes.
A plume of smoke thousands of feet high was visible from Fort Collins, 50 miles away.
Joe Gang, spokesman for the Boulder County Sheriff's Office, issued an urgent plea for more help, saying the 100 firefighters struggling to extinguish the blaze had been slowed by the area's rough terrain.
"We don't have the resources to fight this," Gang said.
The fire started Friday in Walker Ranch Park, an open space area in the Boulder Mountain Parks about 12 miles southwest of downtown Boulder. Authorities evacuated Pine Needle Notch subdivision near the park late Friday.
The blaze was devouring forests of ponderosa pine, douglas fir, Colorado blue spruce and pinon, said Justin Dombrowski, spokesman for the interagency firefighting team.
"This is a serious fire," Dombrowski said. "It's hard to get crews in there and get good work done because it's so steep and rocky."
The cause of the blaze was under investigation, but Dombrowski said there was a "strong possibility" it was started by people, possibly as a campfire.
Doug and Chris Radke from Seattle had been staying with friends in one of the areas that was evacuated. "It seemed to have an incredible appetite. It jumped from one tree to another," Chris Radke said.
In California, firefighters on Saturday were taking control of a handful of fires in central and Southern California, including one blaze that had scorched 11,000 acres.
Two wildfires at the Vandenberg Air Force Base burned nearly 12,600 acres, but firefighters contained the smaller 1,600-acre blaze and had the other nearly surrounded.
The 11,000-acre Harris fire, on the base between Santa Barbara and San Luis Obispo, was about 80 percent contained, said Maj. John Cherry. Earlier in the week, it had forced the evacuation of the town of Casmalia.
Nearly 6.7 million acres have burned across the United States this year, among the nation's worst fire seasons in a half century. As of Saturday, the National Interagency Fire Center reported 23 fires burning in Arizona, California, Colorado, Idaho, Montana, Oklahoma, South Dakota and Wyoming.