Clarks Knob is the highest point on Blue Mountain, the eastern front ridge of Pennsylvania’s Ridge and Valley Appalachians, in Franklin County. Its summit ridge runs northeast to southwest along the mountain’s spine and forms a divide between the Susquehanna and Potomac river drainages, giving it significance beyond its local prominence. Rising more than 1,600 feet above Chambersburg and the Great Appalachian Valley below, it stands as a major geographic feature of the region. The mountain lies within Buchanan State Forest, where it is protected.

Metal, Pennsylvania · USA