The Grand Fire near Frazier park grew to 3,500 acres overnight and is just 15 percent contained Thursday morning.
"The fire remained active last night until approximately 3 a.m.," the Kern County Fire Department said in a statement released about 7:30 a.m. this morning. "Initial efforts this morning will be concentrated on the southern edge of the fire with hand lines and dozer breaks being implemented on the western edge. Helicopters will be assisting crews on the ground."
About 1,000 firefighters are on the scene of the fire, which broke out just after noon on Thursday and forced the precautionary evacuation of Frazier Mountain High School.
Six helicopters, plus fixed wing helicopters are joining hand crews, dozers and engines in battling the fire, which broke out on the west side of I-5 just south of Frazier Mountain Park Drive.
It spread to the south and west, up Frazier Mountain and into the Hungry Valley State Park and Los Padres National Forest.