There's a Sunken Resort at the Bottom of an Ohio Lake That Was Deliberately Flooded in the 1930s Tappan Lake Ohio sunken resort, Tappan Lake Riviera history, Harrison County Ohio lake history, Muskingum Watershed Ohio, submerged structures Ohio, New Deal Ohio reservoirs, underwater Ohio history Before Tappan Lake existed, a valley resort called the Tappan Lake Riviera sat along a creek in Harrison County Ohio. When the dam was completed in 1937 the resort went underwater — and parts of it remain