Firefighters from several agencies are heading into their second day battling a brush fire in East Fork above Azusa.
The Fork Fire left one firefighter with a minor injury and caused campers and visitors using the popular swimming holes in San Gabriel Canyon to be evacuated after it broke out around noon Sunday.
It had burned 60 acres with zero containment as of early Monday morning, according to the U.S. Forest Service.
The fire shut down Highway 39 in San Gabriel Canyon about two miles north of Sierra Madre Boulevard.
Park visitors north of the fire were stuck, their only normal exit from the park cut off to the south, USFS spokesman Nathan Judy said. They were escorted out via a closed section of Route 39 to the Angeles Crest Highway, across a treacherous roadway subject to rockfalls usually closed to the public.
One firefighter suffered a minor injury when he was hit in the leg by a falling rock, Judy said. The firefighter was taken to a hospital for treatment.
Los Angeles County rushed camp crews and other brush teams to the canyon, a heavily wooded area near where several other large wildfires have broken out in years past.
No structures were being threatened, Judy said.
About 300 personnel were battling the brush fire, along with water-dropping helicopters.
The U.S. Forest Service was also being assisted by Cal Fire, Orange County Fire Authority, Ventura County Fire and other fire departments along with the California Highway Patrol and Southern California Edison.
One USFS helicopter will be making night water drops on hot spots, Judy said. County fire sent one water-dropping helicopter, a bulldozer and about 30 personnel, a dispatcher said.
The fire was reported to be burning toward the north, into the rugged central area of the San Gabriel Mountains. It put up a large plume of smoke, visible from as far away as Chino and inland Orange County.
Tanker 911, a jumbo DC-10 jet converted into a fire-suppression tanker, was flown to Southern California from its base near Sacramento to assist in the battle, Judy said.
The cause of the fire remained under investigation.