The fire, which was approximately 3 acres, moved at moderate speeds in the area of the 2900 block of Potrero Road, where some structures were being threatened.
Potrero Road was shut down from Wendy Drive to Hidden Valley Road as firefighters battled the second-alarm blaze.
Flames were spotted moving uphill toward Potrero Road, which runs through the homes in the area. Firefighters from the air and ground appeared to make good progress on the flames closest to the backyards of the properties nearby.