Firefighters face more hot, dry weather Sunday as they struggle to contain a wildfire burning across nearly 20 square miles of dry brush and timber in the Los Padres National Forest.

The blaze broke out Monday about 40 miles north of Los Angeles. More than 1,380 firefighters were battling the blaze and there was no estimate on when it might be contained, said James Turner of the U.S. Forest Service.

No homes have been damaged or were threatened Saturday and no one has been hurt fighting the blaze, he said.

The 12,700-acre fire burned to the shoreline of Pyramid Lake on Friday, forcing the closure of several camping sites and recreation areas and charring three cabanas and picnic tables.

About 1,200 campers and fishermen evacuated when the fire ignited Monday.

High temperatures and low humidity helped the blaze grow exponentially. Cooler overnight temperatures helped slow the fire, but high winds hindered firefighters trying to forge containment lines.

The cause of the blaze, which so far has cost more than $2.4 million to fight, remained under investigation.

In Nevada, improved weather and more manpower helped fire crews hold the line against two fires burning more than 407 square miles in northeastern Nevada.

"The cooler temperatures and moisture are contributing to the success of our suppression efforts," Joe Freeland, fire management officer for the Bureau of Land Management said in Elko.

In Idaho, fires had burned more than 234,000 acres or 365 square miles, according to the Boise-based National Interagency Fire Center, composed of various federal agencies that coordinate to battle wildfires.

In Washington, firefighters battled two of the state's largest wildfires. A fire in southeastern Washington that burned more than 101,000 acres, or 157 square miles, was 55 percent contained, while another in north-central Washington that torched over 170,000 acres, or 265 square miles, was 60 percent contained.

Crews in southern Montana continued to fight a 205,000-acre fire — about 320 square miles. The fire, which started Aug. 22 from lightning, earlier burned 26 homes.