CALISTOGA, Calif. — Despite the efforts of 8,800 firefighters, three major blazes whipping through California’s tinder-dry forests and brush had consumed a combined 270,000 acres and remained largely out of control, state officials said on Monday, forcing thousands of people to flee and destroying up to 1,000 buildings.

At least one person has died in the fires, the governor’s office said on Monday.

By morning, 800 to 1,000 people fleeing one fire’s path had poured into the Napa County Fairgrounds here, sleeping in camping tents, on cots or in their cars. Evacuees who had fled the scorched Lake County communities of Middletown, Cobb, and Hidden Valley Lakes, northwest of Sacramento, told one another their stories of racing the flames and of the last times they had seen their homes.

“We were surrounded on three sides,” said William Slack, 59, a metalworker who goes by the name Jivano and had lived in Middletown, about 90 miles north of San Francisco, for three years. “It was like a furnace. I’ve never seen anything so big before.”

As the flames of what is being called the Valley fire closed in on Saturday night, Mr. Slack abandoned the camper trailer that held all his possessions and decided to evacuate. On his way out of town, he stopped at the home of a friend who had decided to try to defend his home with a garden hose. Mr. Slack said he dragged his friend away as falling embers set a nearby field ablaze.