It has burned about 9,600 acres and is 5 percent contained.
The fire is being fueled by hot weather and extreme winds, conditions that are expected throughout the weekend, Brady said. “The fire jumped a major highway yesterday, and it’s burning on both sides and is being fueled by extremely erratic winds,” she said.
Multiple structures are threatened, damaged or destroyed, Brady said.
California Gov. Jerry Brown has declared a state of emergency, citing “extreme peril” to people and property.
Farther north in Oregon, authorities urged hikers and other outdoors enthusiasts to avoid forested areas near the Oregon-California border, where a blaze has killed one person.
The Jackson County Sheriff’s Office said Friday that although the blaze has not crossed into Oregon, officials are concerned people in remote areas could be unreachable in case they need to quickly evacuate.
The areas of concern include the Pacific Crest Trail, Mount Ashland and the Cascade-Siskiyou National Monument.
Search-and-rescue crews may be prohibited from engaging in search missions because of fire danger, the office said.