The fire was reported at 12:49 p.m. Friday. Several agencies responded to the fire, which burned in brush near the county line.
The brush fire was visible from the freeway, and a SigAlert was briefly issued in the area by California Highway Patrol.
Nearly 100 firefighters were called to the scene and water-dropping helicopters were deployed.
By 6 p.m., crews were beginning to mop up the area.
The cause of the fire was under investigation.
City News Service contributed to this report. null