The Grand Fire near Frazier Mountain Park Road was 90 percent contained Monday morning, Cal Fire officials said.
The blaze, which broke out Wednesday, has charred 4,346 acres.
No homes or other buildings were threatened, but over the weekend, fire officials said the steep and rugged terrain was making it difficult for ground crews to battle the flames.
The cause of the fire remains under investigation.
Crews from Kern, Los Angeles and Ventura counties were on hand with Cal Fire, as well as Los Padres Forest Service, Bureau of Land Management, California State Parks and California Highway Patrol personnel.
Two water-dropping helicopters were also brought in to help fight the fire.
Hungry Valley State Park and Gold Hill Road are scheduled to reopen Wednesday. Frazier Mountain Road is expected to remain closed until Friday.
