Judy Gap, located in western Pendleton County, at an elevation of 2,180 feet, is an erosional notch in standing beds of the hard Tuscarora Sandstone, a major ridge forming stratum. The standing beds at this location are the west limb of the Wills Mountain anticline. The vertical wall of Tuscarora Sandstone parallels the North Fork of the South Branch of the Potomac for miles, forming an alignment of low ridges called the River Knobs, through which many water gaps, such as Judy Gap, have been eroded. Judy Run passes through the gap on its way to the North Fork.

Trails near Judy Gap, which was named for one of the early German-Swiss families who migrated into the area, offer scenic views of Germany Valley, Spruce Mountain (the state's highest), Seneca Rocks, the Fore Knobs, and the Dolly Sods. The Judy Rocks outcrop massively at the gap, and continue as a stony fin through Germany Valley. Judy Gap is a familiar point of reference for hikers, campers, tourists, and others who visit the mountains. The North Fork Mountain Trail in the Monongahela National Forest stretches from Judy Gap to Smoke Hole Caverns. Judy Gap lies south of Riverton and Seneca Rocks, at the intersection of State Route 28 and U.S. 33, which passes through the gap on its way to Franklin, the Pendleton County seat. There is also a community named Judy Gap, as well as the geologic formation.