WEED, Calif. — A wind-whipped fire that erupted near a defunct lumber mill in Northern California on Friday and became a fast-moving inferno has destroyed at least 50 structures, including homes, and prompted the evacuation of thousands of people in rural Siskiyou County, fire authorities said on Saturday.
The blaze, named the Mill fire, tore through Weed, Calif., a working class town of about 2,900 that sits roughly 50 miles from the Oregon border, and damaged nearby communities such as Lake Shastina, with a population of about 2,400; Carrick, home to about 140 people; and Edgewood, which contains about 70.
There were no initial reports of fatalities. Fire authorities said three civilians suffered injuries, though their condition was not immediately known. The blaze had grown to cover 4,200 acres by Saturday night, the authorities said, and was 25 percent contained after being zero percent contained on Friday night.
The number of structures destroyed was expected to rise after teams inspected the damage, said Chris Anthony, the chief deputy director of Cal Fire, the state’s fire protection agency, in a briefing on Saturday. An update later in the day said more than 130 structures had been affected to some degree.
Lincoln Heights, a neighborhood in Weed, was described by one California Highway Patrol officer in the area as “leveled.”
Other areas were left without power, another factor that led many to evacuate, though authorities said electricity would be restored in some locations by Saturday night.
On Saturday afternoon, Weed appeared virtually empty except for the presence of emergency vehicles. Traffic lights were out, the smell of smoke tinged with chemicals hung in the air, and a haze blanketing the area was thick enough to block visibility of the surrounding mountains.
For many residents of the town, fleeing a wildfire is not new. In September 2014, Weed was devastated by the Boles fire, a relatively small but intense blaze that consumed 165 homes and other buildings in the small community. The town is also roughly 30 miles southeast of where the McKinney fire raged this summer and became California’s largest blaze in 2022, killing four people and burning more than 60,000 acres.
Many residents of Siskiyou County have fled to Yreka, a town about 30 miles north of Weed. But even there, signs of the fire were evident, as ashes fluttered down like snowflakes.
At the Black Bear Diner, Bob Noonan and his wife, Loveminda Cidro, a retired couple who have lived in the area for 22 years and had fled, pondered what became of their home. After they had been alerted by a neighbor that they needed to leave, Ms. Cidro said that in the rush to get out she packed randomly, pulling items from the house that did not make sense.
“It was very stressful, I was very nervous, and I was crying when we evacuated,” she said. The couple said they did not expect to be able to return for at least a couple of days.
Jon Heggie, a battalion chief for Cal Fire, said that the first call about the Mill fire on Friday came at 12:49 p.m. from a subdivision in Weed, near a property owned by a wood products company, where some older buildings were undergoing demolition. Within two hours, the blaze had grown to some 900 acres and evacuation orders had been issued for Weed and nearby communities. By 7 p.m., the blaze had grown to 2,580 acres, Cal Fire authorities said.
Kimberly Greene, the mayor of Weed, said that she was at the local community center, rebuilt after a 2014 wildfire, when the spouse of a co-worker ran in and reported smoke in the distance.
“By the time we walked outside,” she said on Friday, “you could see the flames jumping the street.”
The air was hot and dry, she said, and the wind was “howling.” She rushed home and packed her car while fielding reports from fire authorities and from her neighbors.
She said that a number of homes had been destroyed and that the swiftness of the blaze concerned her.
“This one was so fast, I’m worried some people might not have gotten out,” she said.
Jeff Ott, a nurse practitioner from Lake Shastina, was notified by two co-workers and the Siskiyou Sheriff’s Department about the fire that was rapidly approaching his backyard.
Mr. Ott said he saw a “giant column” of smoke, felt the heat of the blaze and heard a roar like a freight train. He grabbed his computers and guitars and was out of his house and in his car in about two minutes, leaving behind framed posters and fliers of punk rock shows from the ’80s that were irreplaceable, he said.
“My car was covered in ashes,” Mr. Ott added. He ended up in a hotel in Yreka and was not sure he had a home to return to — the last he heard, the fire was about 2,500 feet from his house.
The Mill fire was one of at least four sizable California wildfires to ignite in the past four days and came as a massive heat wave roasted the West. Excessive heat warnings are in effect across much of the state.
Los Angeles County firefighters on Saturday were continuing to battle a fire near Castaic that had consumed more than 5,000 acres and that had closed parts of Interstate 5 on Wednesday. Another fire, east of San Diego, led to evacuations earlier this week and closed the Tecate Port of Entry at the border with Mexico. There was little growth from both fires on Friday night, Mr. Anthony said.
In Gazelle, a town roughly 10 miles northwest of Weed, another fire, the Mountain fire, has burned more than 4,800 acres, according to fire authorities. It was 5 percent contained by Saturday night. The extent of the damage there was not immediately known.
Authorities are still investigating the causes of the four fires, but California and other states have been plagued by an ongoing wildfire crisis. Climate scientists say human behavior, mainly the burning of fossil fuels like coal and oil, has released greenhouse gases that increase temperatures, drying forests and priming them to burn.
Earlier this year, fire officials warned of the extreme risk in arid forests and chaparral.
The current heat wave in California has created conditions that can make fires spread more rapidly and sideline firefighters with heat-related illnesses.
Holly Dillemuth contributed reporting.