The blaze began about 2 a.m. in a rugged area about 20 miles north of downtown Los Angeles, fire officials said. About 400 firefighters were on the scene at Angeles National Forest, aided by aerial strike teams, said Los Angeles County fire Inspector Sam Padilla.
One residence and three motor homes were destroyed. A garage and several sheds also burned.
About 1,200 people were evacuated from two canyons as the blaze brushed up against some of the area's 450 homes and moved southeast toward city limits, said U.S. Forest Service spokesman Stanton Florea.
"It burned right down to a couple of neighborhoods," Florea said. It wasn't immediately known whether any homes had been damaged. Television images showed a trail of flames and heavy smoke on a pair of ridges littered with dry brush.