Firefighters gain 40% containment of California’s fourth-largest wildfire on record

CHICO, California — California’s largest wildfire so far this year was 40% contained on Wednesday, after burning more than 670 square miles (1,735 square kilometers).

The massive Park Fire was reportedly caused by arson on July 24 in a wilderness park outside the Central Valley city of Chico and spreading northwards at an astonishing rate under hot and dry conditions, making it the fourth largest wildfire ever in California.

“There was minimal fire activity overnight,” Cal Fire said in its morning summary. “Firefighters are currently working on mop-up and tactical patrol operations to work on containment and to prepare communities for safety for repopulation.”

Much of the fire is in the Lassen National Forest, but authorities say the fire has been contained within existing boundaries.

The weather has been more favourable recently, with higher relative humidity. This humidity can help suppress fires.

More than 5,400 firefighters were still on the scene battling the blaze.

According to Cal Fire, the fire primarily affected two counties, Butte and Tehama, destroying 641 structures and damaging 52.

An arson case is pending against a Chico man who was arrested after a burning car was pushed into a ravine, the Butte County District Attorney’s Office said.

Other large fires currently burning in California have significant levels of containment, except for one that broke out Aug. 9 in Six Rivers National Forest in the northwest corner of the state. The Boise Fire, named after a local creek, was burning more than 11 square miles (28 square kilometers) without any containment as of Wednesday.