A helicopter prepares to set down to load a ninety gallon bucket of water to help combat the forest fire on the Massanutten Mountain between Veach Gap and Sherman Gap in Warren and Shenandoah, Va. counties. (Rich Cooley/AP)

Dozens of firefighters hiked up steep mountain trails in triple-degree heat Friday, as efforts continued to contain a pair of unusual summer wildfires burning over hundreds of acres in the Shenandoah Valley.

Drivers headed into downtown Luray could see a white haze enveloping the top of Neighbor Mountain in Shenandoah National Park. Residents near Front Royal said that at night, they could see bright orange flames on Massanutten Mountain, a few miles away in the George Washington and Jefferson National Forests.

And an easterly breeze meant that residents as far east as Loudoun County and even Silver Spring could smell it. Several people in the region took to Twitter on Thursday morning saying they smelled something akin to burning wood or trash in the air.

The fire on Neighbor Mountain was first reported Tuesday morning. The cause is under investigation. As of Friday afternoon, the blaze was not contained and had spread from 200 to 800 acres, said Shenandoah National Park spokeswoman Karen Beck-
Herzog. The fire on Massanutten Mountain, first reported Monday, was 5 percent contained and covered 353 acres, said U.S. Forestry Service spokeswoman Cindy Frenzel.

Still, the fires were small in comparison with those burning in Colorado. More than 30,000 people have been evacuated since June 23, and more than 18,000 acres had burned.

Wildfires in this part of the country tend to be more common in the spring and fall, when trees are without leaves and the sun is beating down on the forest floor, Frenzel said. But occasionally, drought conditions can exacerbate fire risk at other times of the year.

The rocky terrain at both sites makes fighting fires difficult. In many areas, firefighters cannot get bulldozers in to clear the ground of leaves and other flammable material and dig a fire line to contain the flames. Instead, they must trek for miles in heavy protective gear, carrying shovels, rakes and leaf blowers to get the job done. More than 100 firefighters and support personnel are battling the Massanutten blaze.

Massanutten’s proximity to the Shenandoah River has made it easier for helicopters to fetch water to douse flames. By contrast, to fight the fire on Neighbor Mountain, firefighters have had to get permission from private landowners to access ponds and lakes.

Warren County Fire Chief Richard Mabie spent Friday monitoring the fire on Massanutten Mountain. While county firefighters were not sent up the mountain, they stood ready should the blaze, which has been working its way down the west slope, reach the small number of homes at the bottom. While the fire has the potential to threaten private property, fire officials said they did not think that was likely.

Business was unaffected at the Massanutten Resort, which is 50 miles from the site of the fire. The phone rang with a little more frequency at the visitors center in Luray, with questions about the Neighbor Mountain blaze, but vacationers were not changing their plans, tourism officials said.