Shenandoah Mountain is a prominent sandstone-capped ridge in Virginia and West Virginia that extends about 73 miles through the Ridge and Valley province and forms part of the western edge of the Shenandoah Valley as well as the easternmost Allegheny Mountains. Much of its crest serves as a county and state boundary, and the ridge lies almost entirely within George Washington National Forest, giving it a protected, heavily wooded character. Its highest point is Reddish Knob at 4,397 feet, with other notable summits including Flagpole Knob and Bald Knob. U.S. Route 33 provides one of the main crossings through this rugged barrier.