The fire was reported near the northbound 5 Freeway and Templin Highway. According to authorities, flames from a vehicle fire spread to nearby brush.
A Sigalert was issued for multiple lanes of the northbound 5 because of the fire, causing a major traffic backup.
Officials with the Angeles National Forest earlier said that the blaze had burned 15 acres and was spreading at a moderate rate. As of just before 6:20 p.m., the fire was at 25 acres with 46% containment.
As crews worked to contain the fire, the Los Angeles County Fire Department dispatched fire engines to a nearby mobile home park as a precautionary measure. An evacuation warning for 133 homes has been issued for the Paradise Ranch Estates Mobile Home Park.