Update 8:04 p.m. The Williams Fire in the San Gabriel Mountains, with smoke visible from Redlands and Loma Linda, in the East Fork of San Gabriel Canyon by sundown Sunday, according to the Forest Service.
The point of origin was about half-way between Camp Williams and a shooting range on East Fork Road in San Gabriel Canyon, north of Azusa, 3 to 4 miles east of Highway 39, a USFS update stated.
The fire was burning in medium to heavy brush, all chaparral, on very steep terrain, according to the Forest Service.
Before sundown there were eight tanker planes, five helicopters, 20 engine crews, 12 hand crews, one dozer, and other resources assigned to the fire.
Posted 6:34 p.m. Smoke from a fast-growing fire in the San Gabriel Mountains was visible Sunday afternoon from Redlands, and tanker planes were refueling and taking on more retardant at the Forest Service Tanker Base in San Bernardino.
The blaze was called the Williams Fire, Tanker Base manager Bob Will told Redlands-Loma Linda Patch in a phone interview.
"It was around 400 acres a couple hours ago," Will said. "It might be 500 to 600 by now."
The fire was burning in the Angeles National Forest north of Glendora, and it prompted evacuations at a mobile home park, the Los Angeles Times reported.
Before 6 p.m., one of the orange-bellied tanker planes came in for slow approach over north Redlands before landing at the base on 5th Street.
The DC-10 known as Tanker 911 can carry up to 12,000 gallons of retardant, Will said.