"All of the vegetation in the area is struggling. It's burning very easily," Tolmachoff said. "It causes the fire to be a lot hotter and to spread more easily."
West of Yosemite National Park, a wildfire that began Saturday afternoon quadrupled in size overnight to 2,100 acres, or more than 3 square miles, and was burning out of control Sunday. It destroyed one home in the small community of Foresta, adjacent to the park, Ranger Scott Gediman said. The park itself remained open.
The Sand Fire in the Sierra foothills has prompted authorities to evacuate about 500 homes and close several roads near the town of Plymouth. Nearly 1,500 firefighters, aided by aircraft including a DC-10 air tanker, are working to control the blaze.
CalFire officials say a vehicle that drove over dry vegetation started the fire, which has sent up huge plumes of smoke and worsened air quality in the Sacramento area.
Alfred Shults, his wife, Carolyn, and their granddaughter fled their home in El Dorado County on Friday after receiving an automated telephone call ordering residents to evacuate, according to the Sacramento Bee. Before he left, Shults said he packed as much as he could into his vehicle and turned on a sprinkler to soak the area around his beloved motorcycle.
"We just wanted to get out of there, and hope there's something left when we get back," Alfred Shults, 65, told the Sacramento Bee on Saturday as they waited for news at an evacuation center in Placerville.
Meanwhile, about 400 firefighters aided by fixed-wing helicopters were battling the flames Yosemite, Gediman said. The cause wasn't immediately known.
About 100 homes in Foresta and the small community of Old El Portal were evacuated. Two shelters were opened for people and animals.
"There have been no injuries so far, which is wonderful," Gediman said.
The park itself, home to such sites as Half Dome mountain, Yosemite Meadows, a grove of Giant Sequoia trees and other wonders, remained open Sunday. None of its treasures were threatened, Gediman said, although some areas were smoky.
The Crane Flat campground and Highway 120, a major highway leading to the park from the San Francisco Bay Area, were closed, but other roads were open. So were hotels and other amenities.
Wildfires also burned in other Western states, including Colorado and Utah. The nation's largest wildfire, the 618-square-mile Buzzard Complex in eastern Oregon, was 95 percent contained Saturday. Crews in north-central Washington made progress on the 390-square mile Carlton Complex wildfire that has burned an estimated 300 homes.