As of Wednesday, California’s largest wildfire this year, which has burned over 670 square miles, was 40% contained. The Park Fire, believed to have been started by arson on July 24 near Chico, quickly spread northward in extreme heat and dry conditions, becoming the fourth-largest wildfire in the state’s history.

Cal Fire reported minimal fire activity overnight and noted that firefighters are focusing on mop-up and tactical patrol efforts to enhance containment and prepare communities for repopulation.

Much of the fire is within Lassen National Forest, where it remains contained within its current perimeter. Recent weather conditions, with higher humidity levels, have been more favorable for fire suppression. Over 5,400 firefighters are still assigned to the blaze.

The fire has mainly affected Butte and Tehama counties, destroying 641 structures and damaging 52, as reported by Cal Fire.

An arson case is pending against a Chico man who was arrested after a burning car was observed being pushed into a gully, according to the Butte County district attorney’s office.

Other major fires in California are largely contained, except for the Boise Fire in Six Rivers National Forest, which started on August 9. This fire has covered over 11 square miles and remains completely uncontained.