REMARKS: Devils Den is a series of rock outcrops of sandstone (Shenango Formation(?), Mississippian age) that form several "rock caves" and passageways.
The Nipple (49), about 2.3 miles to the north-east, is capped by a weather-resistant sandstone in the upper part of the Catskill Formation (Devonian age). This small, round, slender erosional feature rises above the surrounding countryside in a spectacular fashion.
REFERENCE: Pennsylvania Geology (1969), Columnar jointing in South Mountain, v. 1, no. 2, p. 7.
REMARKS: A spectacular gorge and scenic view of the High Plateau; site of the famous Kinzua Viaduct, the second highest bridge of this type on the North American continent, 301 feet high and 2110 feet long. The steel structure was built in 1900 as a replacement for the original iron viaduct of the same dimensions built in 1882. The iron viaduct was the highest railroad bridge in the world at that time (1882). The Kinzua Viaduct is in the National Register of Historic Places.