Desert winds and blistering heat Wednesday challenged firefighters battling a 37,000-acre wildfire that destroyed 42 homes, chased up to 1,000 people from small communities but spared historic buildings in a town developed decades ago as a movie set for Westerns.

Temperatures hit 108 degrees as 2,500 firefighters attacked flames devouring greasewood, Joshua trees, pinon pines and brush in hills and canyons of the high desert about 100 miles east of Los Angeles.

“It’s burning vigorously in specific areas,” said Capt. Marc DeRosier of the California Department of Forestry and Fire Protection. Eight air tankers and 13 helicopters attacked from above. Containment was just 16 percent.

The fire, ignited during the weekend by lightning, destroyed 42 houses, 55 other buildings and 91 vehicles, authorities told reporters Wednesday night. They had previously pegged the number of structures destroyed at about 30 but revised that after conducting a detailed count Wednesday.

The fire was moving southwest as winds gusted to 40 mph, DeRosier said, and 800 to 1,000 people remained evacuated from Pioneertown, Burns Canyon, Rimrock, Gamma Gulch, Flamingo Heights and Little Morongo Canyon.

Officials worried that if the blaze continued to move toward the San Bernardino National Forest, it could grow rapidly, threatening the resort community of Big Bear Lake. A bark beetle infestation has killed many trees in the area in recent years, which could provide the wildfire with substantial fuel. “If it starts in there, it will be almost impossible to stop,” said forestry department spokeswoman Karen Guillemin.

Smoke darkened the sky over the Mojave Desert north of the town of Yucca Valley.

Firefighters used picks and shovels against hotspots in the Pioneertown area, where the fire raged Tuesday. There was no damage to the historic area, which dates to the 1940s when Hollywood cowboys such as Roy Rogers and Russ “Lucky” Haden began establishing it as a filming site.

In Morongo Valley — where large ranch homes are surrounded by highly combustible greasewood, Joshua trees, pinion pines and fine brush — residents watched nervously.

“I want to see how bad it is and see if I need to pack up my pictures,” said Tammy Taylor, who drove the family Jeep to the top of the canyon from their nearby home.

An evacuation center was set up at Yucca Valley High School, and horses and other livestock were taken to the town of Landers.

Elsewhere in the West, several new wildfires in southern Montana spread quickly — one to an estimated 10,000 acres — because of windy weather.

At least one house on the Crow Indian Reservation was reported destroyed by a blaze estimated at 4,500 acres, said Jon Kohn, an information officer for the Crow Agency Bureau of Indian Affairs’ Forestry division. There also was a 3,150-acre wildfire west of Columbus, and another burning north of Pompeys Pillar that was estimated at 10,000 acres, said Mary Apple, a spokeswoman with the Bureau of Land Management.