The fire in Pine Canyon, about 50 miles north of Los Angeles, grew to 8,848 acres and burned at least one motor home and another structure, said U.S. Forest Service information officer Ed Gililland.
About 1,400 firefighters were on the lines and containment was put at 47 percent.
``It was a tough night last night,'' he said. ``They're doing heavy structure protection.''
More evacuations were likely in Lake Hughes and Elizabeth Lake, where nearly 600 homes were evacuated Tuesday and Wednesday, he said.
Lake Hughes convenience store owner Linda Martin said she had no plans to evacuate. Her business is an unofficial information center during wildfires.
``The minute a plume of smoke starts anywhere in the area, that's when we start getting the phone calls,'' Martin said. ``This is a pretty close community. Information travels very quickly, and if there's someone in distress or need, everyone's there.''
Monsoonal flow of moist air into Southern California brought thunderstorms that helped firefighters on the lines of the 3,690-acre Verbenia Fire west of Palm Springs in Riverside County. The blaze on the edge of San Bernardino National Forest was 70 percent contained. Two other fires that burned about 500 acres in the county near Lake Elsinore were contained Wednesday.
In eastern San Diego County, the 8,649-acre Mataguay Fire was 90 percent contained after destroying two homes and two outbuildings. Some 1,300 firefighters battled the flames, which were ignited by illegal fireworks near Lake Henshaw. Full containment was expected Thursday evening.
Seventy miles north of Los Angeles, a 625-acre wildfire on the eastern side of the Tehachapi Mountains was 90 percent contained after destroying a house and motorhome in Cameron Canyon. Full control was expected by Thursday evening, said Kern County fire Capt. Doug Johnston.
In the Sierra Nevada, a lightning-sparked wildfire in Yosemite National Park grew to 1,700 acres. Hikers were evacuated and trails were closed in part of the park earlier in the week when the blaze, one of nine naturally ignited two weeks ago, suddenly expanded.
In Los Angeles, authorities were investigating a brush fire that erupted Wednesday in the wilderness of Griffith Park two days after a fire broke out in the same area. A rapid firefighting response held the first blaze to four acres and the second to 12 acres. A Boy Scout camp had to be evacuated both times.