The Kinzua Dam, on the Allegheny River in Warren County, Pennsylvania, is one of the largest dams in the United States east of the Mississippi River. It is located within the Allegheny National Forest. The lake extends 25 miles to the north, nearly to Salamanca, New York, which is within the Allegany Reservation of the Seneca Nation of New York. Federal condemnation of tribal lands to be flooded for the project displaced more than 600 Seneca members and cost the reservation 10,000 acres (4,000 ha), nearly one-third of its territory and much of its fertile farmland.