The fire was reported just after 1 a.m. near Grant Line Road north of Interstate Highway 580 in the area of the Altamont Pass, California Highway Patrol Officer Ralph Caggiano said.
Firefighters from multiple agencies, including the Alameda County Fire Department and the Tracy Fire Department, contained the flames by 2:50 a.m.
No injuries were reported.
The cause of the fire remains under investigation.
