The Allegheny Mountain and Big Run Trailhead provides access to Big Run Trail (Forest Trail 527), which runs along the east bank of Big Run in Monongahela National Forest.

Two parking access points are available: one at the northernmost oxbow of Forest Road 112 and another off Sawmill Run Road/Forest Road 28/10 via Gatewood Trail, offering hiking opportunities through scenic forest and wetland areas with historic remnants of an old rail line.