Firefighters called for reinforcements Wednesday to battle a wildfire (search) that had blackened 1,500 acres on steep mountain slopes about 35 miles northwest of Las Vegas (search).

The fire, started Monday by a truck crash in the Humboldt-Toiyabe National Forest (search), was 20 percent contained. No structures were threatened and no new evacuations were ordered.

"We've asked for some additional resources, including air support, and it could be arriving today," said Robbie McAboy, a spokeswoman for the firefighters.

Favorable breezes Tuesday helped steer the fire away from the Kyle Canyon community and its only access road.

"There's a collective sign of relief," said Scott Dinger, 39, a North Las Vegas police officer who hiked from his canyon home to a nearby ridge to watch the firefighting.

A mountaintop Girl Scout camp and a youth correctional facility were evacuated Monday and homeowners were ordered out of about 15 homes in a development near the fire lines. About half the 900 residents of Kyle Canyon left voluntarily, authorities said.

Elsewhere, the huge wildfires that have charred interior forests in Alaska for weeks were slowed by rain, and cooler temperatures were expected, the National Weather Service (search) said.

Fires have spread across 4.45 million acres in Alaska, making this the second-largest fire season since the state began tracking. There were 120 active fires on Tuesday. However, because of the sparse population and vast acreage of Alaska, only 35 structures, mostly cabins and secondary homes, had been destroyed.

Also in Nevada, a fire started by teenagers playing with fireworks destroyed four homes in northeast Reno, but firefighters quickly extinguished the blaze and no one was hurt.