The fire had reportedly burned approximately 50 acres by 9:30 p.m. Monday. The fire was estimated to be about 50 percent contained.
The fire was burning along the 101 Freeway near Hampshire Road near the 23 Freeway.
No injuries were reported.
The fire approached nearby industrial buildings, but firefighters extinguished threatening flames.
No evacuations were ordered.
Fire engines, bulldozers and helicopters were assisting about 200 firefighters at the scene.
The cause of the fire was under investigation.
The Associated Press contributed to this report.