The fire was reported at 6:47 p.m. in the area of Hall and Donald drives.
When fire crews arrived, they found about an acre of vegetation burning on a steep slope. The fire was threatening three structures on Keith Drive, according to the fire district.
A total of about 70 personnel attacked the blaze using eight engines, two ambulances, a helicopter and two hand crews. The fire district received mutual aid from the Contra Costa County Fire Protection District, East Bay Regional Park District and Cal Fire.
The fire burned about one and a half acres and was out by 7:30 p.m. No injuries were reported.
The cause of the fire was still under investigation today, Fire Marshal Michael Mentink said.