The Park Fire had burned more than 350,000 acres (141,640 hectares) about 90 miles (144 km) north of the state capital city of Sacramento as of Saturday evening, according to the California Department of Forestry and Fire Protection, or Cal Fire, Reuters reported.
Cooler temperatures and more humid air were expected in the region, potentially helping efforts to slow the spread of the fire, which was 10% contained as of Saturday evening. The fire has destroyed 134 structures, authorities said.
Evacuation orders and warnings were issued for multiple communities in several counties, including a warning for Paradise, the town that was devastated by the 2018 Camp Fire, the deadliest in the state's history.
US President Joe Biden has been briefed on the fire and has directed his team to do everything possible to support efforts to fight it, a White House official said.
A man was arrested on Thursday on suspicion that he started the Park Fire by pushing a flaming car into a gully on Wednesday afternoon.
The fire was the largest of dozens of active blazes across the country that have burned more than 2 million acres, according to the National Interagency Fire Center.
In Oregon, several fires were burning, including the Durkee Fire, which had scorched more than 288,000 acres in the eastern part of the state, authorities said.
A firefighter died after a single-engine tanker crashed near the Falls Fire in southeastern Oregon, the US Forest Service said in a statement on Friday.