Updated

A smoky mountain wildfire destroyed three houses and forced hundreds of people to leave their homes despite progress Monday clearing fire lines west of a California lake near Bakersfield, officials said.

At least two of the burned houses appeared to be abandoned, the U.S. Forest Service said in a statement.

One other home was damaged by the blaze that charred about 3.4 square miles of trees and brush in and around Sequoia National Forest.

Power lines and communications facilities were also under threat.

Firefighters using air tankers and helicopters were battling the fire, which was about 10 percent contained. On Monday, firefighters succeeded in digging a fire line almost all the way around the blaze and were burning vegetation in the fire's path.

"It's running out of fuel basically, and it is burning downhill, so the fuel load is lighter as it goes downhill to brush and grasses rather than conifers," said fire spokeswoman Cheryl Chipman. She said lighter winds were also expected in coming days.

"We are optimistic and expecting a good report from the crews," Chipman said.

Flames that were being pushed by gusty winds from the west came within a mile of the mountain community of Wofford Heights, and authorities called on residents of about 1,000 threatened homes to evacuate. Dozens of people stayed at a Red Cross shelter overnight, and residents of 500 homes were under mandatory evacuation.

The fire broke out Friday night in a remote area about 40 miles northeast of Bakersfield and expanded Saturday as dry winds pushed the flames toward homes, prompting Kern County sheriff's deputies to knock on doors into the night to urge residents to leave.

More than 1,100 firefighters were battling the blaze in the steep, rugged terrain at elevations of up to 4,000 feet in a popular outdoor recreation area of the southern Sierra Nevadas. Aircraft were scooping water from Lake Isabella to use on the flames. Helicopters flew around the clock and crews were able to keep the fire from growing significantly.

There is no projected containment date and more crews were expected to join the fight. Authorities planned to keep the augmented crews working so they don't lose any time during shift changes to make progress, Forest Service spokeswoman Jennifer Chapman said.

"It's going to be even hotter and drier at the end of the week," she said.

The Forest Service said that camping, horseback riding, rafting and other activities in the Sequoia district were so far unaffected by the blaze.