Flames broke out just after 3 p.m. Sunday and charred 35 acres. The fire burned near the 215 Freeway south of UC Riverside.
Nearly 100 firefighters battled the fire from the ground and in the air. Two air tankers were making drops.
The California Highway Patrol was also on the scene helping with traffic control.
No homes were evacuated.
One firefighter sustained a minor ankle injury.
Fire crews planned to be at the scene all night looking for potential flare-ups.