U.S. Forest Service spokesman Jake Rodriguez says the fire is 80 percent contained Saturday.
The blaze began Thursday afternoon in an orange grove in Temescal Canyon, a hilly area south of Corona.
No homes are threatened. Three firefighters have been treated for minor injuries.
About 100 firefighters, aided by aircraft, are on the scene some 50 miles east of Los Angeles.
The cause of the blaze hasn’t been determined.
(© Copyright 2011 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)