PETERSBURG, W.Va. — Forestry officials say a wildfire in West Virginia forest has grown to 100 acres.

The U.S. Forest Service says in an incident report that 34 firefighters and a helicopter are battling the blaze in the Monongahela National Forest.

The so-called North Fire is located in a remote area of Grant County, about 12 miles west of Petersburg. Officials say it is 20 percent contained.

Officials say the fire is in a treacherous area with falling trees and loose rocks. The Landis Trail and the Redman Run Trail are closed. A large portion of the North Fork Mountain Trail also is closed.

Forest visitors are being advised to use extreme caution with campfires.