ABSTRACT
Kinzua Dam and Allegheny Reservoir provide the opportunity to see the effect of the geomorphology of the upper Allegheny Basin on the construction of a major reservoir project. The Kinzua Col probably had a summit elevation comparable to the low divides on the plateau in the vicinity of Big Bend. The gorge downstream of Kinzua, Pennsylvania, was a textbook illustration of a site for a dam, with the valley widening upstream to provide a reservoir of much greater width than at the damsite. The Kinzua Dam was sited at the location of a preglacial col in a well-developed, dendritic drainage system in the Allegheny Plateau of Northwestern Pennsylvania. The Illinoian ice sheet blocked the northwestern course of the ancient Allegheny River, ponding its waters in front of the ice in the glacial foreland until they overtopped the col and eroded a new valley to the ice-free southwest to form the present Allegheny Valley.
