LOS ANGELES — Wildfires continue to devastate the northern forests of California as scorching heat and severe drought are creating ideal conditions for conflagrations.
The River Fire, which broke out about 20 miles southwest of Yosemite National Park on Sunday afternoon, exploded to 2,500 acres in just a few hours and had spread to 4,000 acres by Monday morning, officials with the California Department of Forestry and Fire Protection, or Cal Fire, said.
More than 450 personnel — including some using air tankers — were battling the blaze, which was 5% contained.
Mandatory evacuation orders were in place in parts of Madera and Mariposa counties. The cause of the fire is under investigation, Cal Fire said.
Dangerous heat, persistent drought and low humidities are priming California for extreme fire behavior, experts say.
North of the River Fire, the lightning-induced Beckwourth Complex Fire, which includes the massive Sugar Fire, ballooned to 89,748 acres. The Sugar Fire, which ignited July 2, more than doubled in size over the weekend, growing to 89,078 acres, according to Plumas National Forest officials. It is now the state’s largest fire of the season so far.
The fire, which is burning north of Lake Tahoe, has spread most rapidly on its north side, said Kimberly Kaschalk, a public information officer with California Incident Management Team 4. The fire is 8% contained, with much of its southern flank extinguished.
The other blaze in the Beckwourth Complex Fire — the Dotta Fire — started June 30 and charred 670 acres. It was 99% contained by Monday.
Authorities received reports the Sugar Fire is destroying homes in multiple communities, but no official figures have been released, Lisa Cox of the U.S. Forest Service, who is a public information officer for the Beckwourth Complex Fire, said on Sunday. Video posted to social media showed homes ablaze in the town of Doyle. A damage assessment team was working on a tally.
The Plumas County Sheriff’s Office has issued evacuation orders for Frenchman Lake and Dixie Valley. The Lassen County Sheriff’s Office issued evacuation orders for areas west of Highway 395 from County Road A25 to the Lassen-Sierra county line, as well as for the town of Doyle. An evacuation shelter has been set up at Lassen County Fairgrounds.