Firefighters are trying to figure out how two wildfires began along Massanutten Mountain.

One fire has grown to nearly 400 acres.

The second, just a short distance away, has grown to nearly 100 acres.

The Virginia Department of Forestry, the U.S. Forest Service and the U.S. Park Service have all been working together to try and put out the fires that have been burning since early Sunday afternoon.

"The fire spread quickly due to dry conditions," says Joseph Lehnen, with the Virginia Department of Forestry.

He says the cause of the fire is under investigation.

"We can probably safely say it was human caused because there was no lightening in the area," says Lehnen.

When it comes to battling two mountain fires so close together, Lehnen says it becomes difficult and hazardous.

"On steep terrain like this, there's rolling rocks that we have to deal with, there's dead trees that could fall down, there's just a plethora of safety issues that we have to take care of," adds Lehnen.

Residents saw thick smoke coming from the mountain in Fort Valley, Route 232 near Page Valley Estates and the Caverns Golf Course area.

Lehnen says while the flames still light up the night's sky, it has been contained.

"We made sure residents in the area are safe for the night," says Lehnen.

About 100 firefighters are working on both fires. They're using a helicopter to dump water on the flames and a bulldozer is being used to get through the tough terrain.

Lehnen says he's hopeful that expected rainfall in the Valley will help put the flames out for good.

"If we get rain, we'll have a monitoring crew here. f we don't get rain, then we'll be back in full force," says Lehnen.

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