The fire began at about 4 p.m. Tuesday in the area of Curry Canyon Road, southwest of Morgan Territory Road on the east side of Mount Diablo. It was declared fully contained at about 6 p.m. Thursday.
The blaze had threatened about six homes and 20 outbuildings in the area, but none were damaged.
Two firefighters suffered minor injuries while battling the fire, which burned grass, brush and oak woodlands in the remote area.
Crews are still at the scene today cleaning up the area, and the cause of the fire is still under investigation, Crawford said.