LOS ANGELES >> A new wildfire spread today at a staggering pace in every direction through drought parched canyons east of Los Angeles, growing to 14 square miles in a matter of hours and forcing the evacuation of more than 82,000 of people from mountain communities.

The blaze in Cajon Pass caused serious problems for a swath of mountain communities. About 82,500 people from some 34,500 homes were under mandatory evacuation orders, San Bernardino County fire spokesman Eric Sherwin said. Some structures had already burned but it wasn’t yet clear whether they were homes.

Evacuated areas included the ski-resort town of Wrightwood, where some 4,500 people live.

The flames also forced the shutdown of a section of Interstate 15, the main highway between Southern California and Las Vegas.

As that fire surged, a major blaze north of San Francisco was fading and some 4,000 people in the town of Clearlake were allowed to return home.

Their relief, however, was tempered with anger at a man who authorities believe set the blaze that wiped out several blocks of a small town over the weekend along with 16 smaller fires dating back to last summer.

The wildfires were the latest in a weekslong stretch of heat- and drought-driven fires across California that raged well before the official start of wildfire season in early autumn.

Blue Mountain Farms, a horse ranch in Phelan, was in the path of the fire about 60 miles east of Los Angeles — just as it was for another fire in the area a year ago.

“Breathing smoke again, just like last year,” Shannon Anderson, a partner in the ranch, said as she panted into the telephone. “It’s raining ash.”

Ranch hands used hoses to wet down fences and anything else that could burn.

Six firefighters protecting homes were briefly trapped by flames and in serious danger before they took shelter in a safe structure, the San Bernardino County Fire Department said in a statement. Two sustained minor injuries and were quickly treated and released from a hospital.

Investigators in Northern California said today they had been building a case against the suspected arsonist, 40-year-old construction worker Damin Anthony Pashilk, for more than a year but did not have enough evidence to make an arrest until the weekend blaze ripped through Lower Lake.

Nearly a decade ago, Pashilk was an inmate firefighter while serving time on drug possession and firearms charges, according to California corrections department spokeswoman Vicky Waters. He was completing a five-year sentence when he was assigned to fight wildfires for four months in 2007.

The fire destroyed 175 homes, Main Street businesses and other structures in the working-class town of Lower Lake.

“What I’d do to him, you don’t want to know,” said Butch Cancilla, who saw his neighbor’s home catch fire as he fled on Sunday. Cancilla still doesn’t know the fate of his own home and spoke at a center for evacuees set up at a high school.

“A lot of people want to hang him high,” his wife, Jennie, added.

Pashilk has not been implicated in any of the three huge blazes that destroyed more than 1,000 homes in Lake County last summer. Little was known about him, other than his history of drug and driving offenses dating back a decade.

“I’m hoping, I’m praying that the man has mental illness — because if it’s not mental illness, then it’s evil,” said Diana Bundesen, who was at the evacuation center after fleeing Clearlake.

The town was near the site where the fire began.

Neither the California Department of Forestry, which led the investigation that resulted in Pashilk’s arrest Monday, nor the Lake County sheriff or district attorney would discuss what led authorities to him.

“Arson investigations are complex and difficult. The evidence standards are stringent,” forestry department spokeswoman Janet Upton said. “They have to build a case that is going to be successful, it’s complex.”

An attorney listed as representing Pashilk did not return a call requesting comment. Pashilk is scheduled to be arraigned Wednesday.

Roughly 1,600 firefighters were making progress on the blaze as it burned through wilderness. It was 20 percent contained.

In central California, a wildfire near Lake Nacimiento destroyed 12 structures, damaged others and threatened 200 homes. It was 10 percent contained after growing to 10 square miles and forcing authorities to evacuate some residents by boat.