Firefighters battling a newly merged pair of wildfires feared the blaze could create disastrous weather Saturday and hinder progress in blocking the fire from reaching the populated San Bernardino Mountains.
The lightning-caused fires, covering about 108 square miles combined, merged Friday afternoon in craggy, brush-covered hills just northeast of the mountains, where millions of trees killed by drought and bark beetles could provide explosive fuel.
When fires become intense enough, they can generate their own winds and become highly unpredictable. But in this case, "there was no cataclysmic event," said U.S. Forest Service spokesman Jim Wilkins.
But officials were concerned that the unforgiving desert heat, erratic winds and rugged terrain will challenge firefighters in the coming days. Fire heat rising into the atmosphere could produce dry lightning Saturday.
"That will not only start new fires, but also strike firefighters," said National Weather Service forecaster Robert Balfour. He said thunderstorms, gusty winds and rain was also in the forecast for the next several days.
The larger of the two fires has destroyed 56 homes and 163 smaller buildings such as sheds, officials said. The 59,000-acre blaze, about 92 square miles, began a week ago on the Mojave Desert floor below the eastern flank of the San Bernardinos, and was 35 percent contained.
The smaller fire had burned 10,000 acres roughly 16 square miles and was 5 percent contained. Though heavy smoke filled the sky Friday, wind was pushing that fire away from the mountaintop Big Bear resort region and back onto areas already burned by the larger fire. People began packing suitcases but otherwise stayed put.
Thousands of people live in and around Big Bear Lake, a popular summer destination about 80 miles east of Los Angeles which went through its last big scare in Southern California's onslaught devastating wildfires three years ago.
Resident Jeri Stayer packed clothes and personal documents and had her cat's carrier ready to go, just in case. But Stayer, her husband, their 13-year-old daughter and the cat didn't think it was time to leave.
"Maybe if we saw flames down the street, but we have a lot of faith in the firefighters," Stayer said.
Another resident, 51-year-old Wendell Cole, also was relying on faith.
"God put the fire out when it was coming over last time," said Cole, referring to a snowfall that helped firefighters control the 2003 blaze. "We trust the Lord."
Despite low humidity, steep, broken slopes and 105-degree temperatures, firefighting efforts were in "great shape," Wilkins said. About 2,900 firefighters and three dozen aircraft were fighting the blazes.
In Pioneertown, a former Western movie locale where the larger fire burned several homes this week, a search and rescue team planned to head back out to look for a 57-year-old man missing since Tuesday. The wife of Jerry Guthrie reported him missing.
A 500-acre blaze near the city of San Bernardino threatened about 100 homes and was 20 percent contained, fire officials said. The fire, which began Friday night, destroyed one outbuilding.
Meanwhile, in southern Montana, firefighters mostly east of Billings were battling four large fires that charred tens of thousands of acres Friday evening. The fires threatened hundreds of homes, including roughly 150 homes, officials said.