Firefighters battled Monday to save hundreds of homes threatened by a stubborn wildfire that broke out over the weekend in tinder-dry brush and raced over hillsides and through canyons in northern Los Angeles County (search).

Although no houses have been lost, nearly 1,600 homes have been evacuated since the fire began Saturday. It was ignited when a red-tailed hawk flew into a power line, was electrocuted and its flaming body fell into brush.

The wildfire had spread across about 6,000 acres by Monday evening and was 45 percent contained. Helicopters dropped water to slow the flames as bulldozers and hand crews working in 90-degree heat labored to cut a line around the fire.

"It looks a lot worse than it actually is," said Martin Esparza, a U.S. Forest Service (search) spokesman. "The winds have started mellowing out and the temperatures have started to drop just a bit."

The fire was one of several burning across more than 40,000 acres of California, from eastern San Diego County to Yosemite National Park.

One of the largest of the others, 90 miles east of Los Angeles in Riverside County, has destroyed four mobile homes, 14 outbuildings and more than a dozen vehicles. It was expected to be fully contained by Tuesday morning.

That fire was started by a target shooter, who was given a citation and may have to pay costs of fighting the fire, said Jim Boano, a spokesman for the California Department of Forestry.

About 15 miles west of downtown Modesto (search), a wildfire burning out of control along the San Joaquin River spread to 1,000 acres Monday, and was threatening several homes. The fire burned through dense brush into a restored habitat area for the endangered riparian brush rabbit, said Stanislaus County fire Deputy Chief Jim Weigand.

Elsewhere, firefighters made steady progress against a fire about 45 miles north of Los Angeles that has burned more than 17,000 acres since it started July 12.

The fire, which was about 90 percent contained Monday evening, has destroyed three homes. It was expected to be contained by Friday.

In Yosemite National Park, a lightning-sparked wildfire that has closed a number of trails was being allowed to grow on one front but was otherwise mostly contained, park officials said. The blaze has burned across more than 3,800 acres.

In Nevada, officials said a ferocious wildland fire that destroyed 15 homes in Carson City was traced to an illegal campfire. That fire was nearly contained Monday.

In Alaska, an evacuation alert was issued Monday for about 80 homes north of Fairbanks after winds pushed a 473,000-acre fire within 31/2 miles of the area, fire managers said.

Alaska has been having one of its worst wildfire seasons in years, with 3.6 million acres already burned. However, most of the state's 107 fires are in Alaska's remote and unpopulated forests, and many are being allowed to burn.