 The Reedsville Shale is stratigraphically above them, and overlain by the ridge forming Bald Eagle Sandstone.The valley has been intensely karstified, as evidenced by the numerous sinkholes, springs, caves, and disappearing streams.Within a number of caves in this valley a new species of fish, a type of troglomorphic sculpin, was identified in 2003 by Luis Espinasa, an associate professor of biology at Marist College.