Fires have burned around 30,000 acres of forest as of Saturday, September 12, California's wildfire authority, Cal Fire, said.
The Bobcat Fire, which started September 6, is only 6% contained and has already razed 30,000 acres, including in the Angeles National Forest, Cal Fire reported on its website.
In a video shared with Reuters, fierce flames engulfed trees near a picnic area at the forest.
"This fire has mainly been driven by steep terrain and dry fuels, some of which have not seen fire activity in at least 60 years," Angeles National Forest said on its website.
In California, tens of thousands of firefighters were battling 28 major wildfires as of Saturday afternoon and improving weather conditions have helped them gain a measure of containment over most of the blazes, Cal Fire said.