Pymatuning State Park occupies 3,512 acres in northeastern Ohio along the Ohio portion of Pymatuning Lake, part of a larger recreation area shared with Pennsylvania. The region was once a swamp inhabited by Native peoples including the Mound Builders, Lenape, and later Seneca before U.S. control followed General Anthony Wayne’s campaign and the Treaty of Greenville. Settlement was difficult because of wet ground, quicksands, predators, and disease. After flooding intensified interest in damming the Shenango River, construction began in 1931 and created a vast reservoir completed in 1934. Today the area is a major destination for boating, fishing, camping, and wildlife viewing.