The fire grew to 1,000 acres by 7 p.m. The fire is not contained.
About 200 homes in the Green Valley area were evacuated earlier in the evening. The Los Angeles County Sheriff's Office said mandatory evacuations for Green Valley community were lifted as of 10 p.m.
The American Red Cross Los Angeles Region has set up a shelter for evacuated residents at the recreation center of Marie Kerr Park, located at 39700 30th Street West in Palmdale.
San Francisquito Canyon Road and Elizabeth Lake Road are closed to Spunky Canyon Road. Bouquet Canyon and Elizabeth Lake roads are under soft closures and are open to residents only.
The fire broke out near LADWP's Power Plant I near San Francisquito Canyon and Powerhouse roads around 3:30 p.m. A DWP power plant operator first noticed the fire and notified Los Angeles County Fire, according to DWP spokesman Joe Ramallo.
One structure believed to be a DWP structure has burned. Two other structres have been damaged.
The flames also burned beneath power lines. Power was rerouted away from the threatened lines. No power outages were reported. Power supply is safe and DWP is monitoring, according to Ramallo.
Ramallo said the moderate temperatures meant lower energy demand, which helped DWP operations as the fire burned.
Los Angeles City Fire sent units to help in the firefight.
Rescue helicopters were searching for nine hikers believed to be in the area, according to the L.A. County Fire Department. One hiker was located and was determined not to be in danger. By 9 p.m. all of the hikers were accounted for and were not in danger.
The cause of the fire was under investigation.