The park is at an elevation of on the Allegheny Plateau, which formed in the Alleghenian orogeny some 300 million years ago, when Gondwana (specifically what became Africa) and what became North America collided, forming Pangaea. Although the gorge and its surroundings seem to be mountainous, the area is a dissected plateau. Years of erosion have cut away the soft rocks, forming the valleys, and left the hardest of the ancient rocks relatively untouched on the top of sharp ridges, giving them the appearance of "mountains".