The blaze destroyed 50 buildings and forced the evacuation of 1,000 people, officials said.
The cause of the day-long fire remains under investigation and evacuation orders are in place for Weed, Lake Chastina and Edgewood.
“This incident is rapidly evolving and our staff and partners are doing everything they can to get everyone to safety,” the Siskiyou County Sheriff’s Office said.
Officials in Siskiyou County are also battling the Mountain Fire, which has grown to 4,812 acres with 5 percent containment.
The fire was burning on steep terrain and was seen spreading, prompting the evacuation of more than 300 people, according to Cal Fire.
“The fire continues to burn through trees. The fire was very active overnight. The fire is moving north,” the Cal Fire Siskiyou Division said.
The cause of the mountain fire remains under investigation and evacuations have been ordered.
Meanwhile, in Southern California, the Root Fire in Los Angeles County was 87% contained at 5,208 acres Saturday evening, according to an update from the Los Angeles County Fire Department.
Two structures were destroyed and hundreds more were threatened, the fire department said.
Firefighting operations continued overnight with a focus on mopping up hot spots and further building containment lines, the update said.
“Today underground resources are focused on clearing hot spots. High heat, low humidity and steep terrain continue to be the biggest challenges for firefighters,” the fire department said.