Firefighters dug in for another day of blistering heat Thursday as they struggled to keep a string of desert wildfires from spreading toward the mountain resort community of Big Bear Lake.
The lightning-sparked flames had already destroyed nearly 100 homes and other structures and chased about 1,000 people from Rimrock, Burns Canyon, Gamma Gulch, Flamingo Heights, Little Morongo Canyon and the Wild West film community of Pioneertown, officials said.
It was worst combination for firefighters, reports : dry brush, hills that haven't burned for years, temperatures over 100, and low humidity.
"We're talking about steep hills that make progress by hand crews and engines slow and difficult," San Marcos Fire Battalion Chief Rick Vogt told CNN Thursday morning. "That, combined with the weather, makes it a challenging fire."
Air power was helping to slow the fire down, but the weather continues to heat up, reports CBS News correspondent Vince Gonzales.
A 37,000-acre blaze threatening Pioneertown was one of several fires started by dry lightning that moved through the area earlier this week, Vogt said.
Fire officials worried that if the fires continued west toward the San Bernardino National Forest, they could grow rapidly in the steep terrain and get dangerously close to Big Bear Lake, a community of summer lake and winter ski resorts and about 5,500 residents.
A severe bark beetle infestation has killed many trees in recent years, and the dry trees would fuel the flames.
"If it starts in there it will be almost impossible to stop," said California Department of Forestry spokeswoman Karen Guillemin.
At least 42 houses, 55 other buildings and 91 vehicles have burned in around the high desert communities about 100 miles east of Los Angeles, authorities said. Most of the historic buildings that made Pioneertown famous, old west saloons and storefronts that once were props for movie cowboys like Gene Autry and Roy Rogers, were spared. Some privates homes were not.
"Here's the front door over here. This was the living room," one homeowner told Futterman.
Temperatures hit 108 degrees Fahrenheit Wednesday as 2,500 firefighters attacked flames devouring Joshua trees, pinon pines and brush in hills and canyons. Highs in the 100s are forecast for the Pioneertown area through the weekend. Higher up at Big Bear Lake, temperatures in the mid-80s were forecast for Thursday.
North of Yucca Valley, a blanket of smoke darkened the sky over the Mojave Desert.
In the Gamma Gulch area, dead animals littered a property where a home and barn burned. Eight firefighters and two civilians were treated for minor burns or smoke inhalation.
Elsewhere in the West, several new wildfires in southern Montana spread quickly — one to an estimated 10,000 acres — because of windy weather.
Wildfires have burned more than 4 million acres across the United States, almost twice the 10-year average for this time of year, according to National Interagency Fire Center.