The fire appears to have started around 4:50 p.m. Friday when a car went off the roadway in the area of Deer Park and Sanitarium roads and sent a spark into the brush, said Cal Fire spokeswoman Suzie Blankenship.
About 495 firefighters remained on scene this morning, and full control of the blaze is expected by Monday, Blankenship said.
Two minor injuries were reported and three structures, a house and two outbuildings, have burned, Blankenship said.
Residents in the area of the fire were initially evacuated but the evacuation orders have since been lifted and all roads in the area are open, Blankenship said.
