120 fire fighters are battling to contain the blaze, which has destroyed 20 structures, KEYT reported.
The California Department of Forestry and Fire Protection ( CAL FIRE) in a release issued at 7.30 p.m. local time (10.30 p.m. EDT) said, "Fire is 1000+ acres and 0% contained with multiple structures threatened".
The fire spread to more than 20,000 acres, forcing the evacuation of small communities, including Hornbrook, where an unidentified body was found Friday morning in a burned out home. No cause has been determined, but the Santa Barbara County Fire Department said there is now an active investigation.
The fire is located about a mile northwest of Basalt and was started Tuesday by two people firing tracers at a firing range near Christine Lake.Three houses have been destroyed.
California Gov. Jerry Brown has declared a state of emergency for Siskyou County, citing "extreme peril" to people and property.
Authorities announced that mandatory evacuation orders were being greatly reduced and numerous 2,500 people who fled Friday night would be able to return home by late afternoon.
Farther south, a fire in the San Bernardino National Forest grew to 1,000 acres and prompted the evacuation of Forest Falls, a town of about 700 homes.More news: The Meghan Markle British Accent Uproar Needs to Chill
Officials ordered mandatory evacuations for residences served by Highway 128 between Monticello Dam and Pleasants Valley Road, and west of Highway 16 to Berryessa Knoxville Road, south of Old County Road 40 and north of County Road 53.
What's happened: Cal Fire spokesman Brice Bennett said no homes were destroyed, but seven outbuildings have been damaged.
Meanwhile, in Northern California, at least one person has died in the Klamathon Fire, which began near the OR border.
County Fire Chief Eric Peterson thanked residents for heeding the call to evacuate, allowing firefighters to focus on fire suppression rather than rescues.
Firefighters battling wildfires throughout the U.S. West that have torched hundreds of homes got some help from the weather Saturday, even as they tallied damage from new fires that erupted amid a Southern California heat wave.
Regarding evacuations, the Santa Barbara Sheriff's Office said on Twitter, "alerts were sent to those affected by zip code".
Some fires have been calmed by rain while others have been stoked by wind and hot temperatures. That blaze destroyed more than 1,000 buildings in Ventura and Santa Barbara counties. More than 3,600 personnel are fighting the fire. Saturday morning, Cal Fire San Diego tweeted that firefighters continue to make progress, and containment has risen to 30 percent.