Updated

A fast-growing wildfire was burning Thursday night near power stations and utility lines north of Los Angeles and homes in a mountain community were being evacuated, officials said.

The fire in the Angeles National Forest surged to 500 acres after burning for about three hours, the U.S. Forest Service said, sending out big clouds of black smoke amid temperatures in the high 80s and winds gusting at more than 20 mph.

The Los Angeles County Sheriff's Department was helping residents evacuate in the community of Green Valley. It was not clear how many homes are threatened, but about 1,000 people live in the area.

Both Southern California Edison and the Los Angeles Department of Water and Power said the fire was threatening their facilities and they were monitoring the blaze for potential outages, though none had been reported. Power was being rerouted away from the threatened lines.

The blaze broke out at about 3:30 p.m. just north of Powerhouse No. 1, a hydroelectric plant near the LA aqueduct that was the first to bring municipal power to the city and has been operating for nearly a century.

One structure has burned but it was not immediately clear what it was.

Further north near Santa Barbara, a fire that burned nearly 2,000 acres in the Los Padres National Forest and forced the evacuation of thousands of campers when it broke out on Memorial Day was fully contained Thursday.