Lake Oahe Pierre, South Dakota and extends nearly as far north as Bismarck, North Dakota. Mobridge, South Dakota is located on the eastern shore of the central portion of the lake. Bridges over Lake Oahe include US Route 212 west of Gettysburg, South Dakota and US Route 12 at Mobridge. The former town of Forest City has been flooded beneath Lake Oahe, about 9 miles west of Gettysburg. Prehistoric archaeological sites have been explored in the area, including Molstad Village near Mobridge. It dates to before the emergence of the Arikara, Hidatsa and Mandan as separate peoples, and has been designated as
Norris Dam State Park dam to the base of River Ridge at the Claiborne-Grainger county line. The lake also spans the lower of the Powell River from the river's mouth to a few miles south of Harrogate, and the lower of Cove Creek. The Norris Dam Reservation, which is managed by the Tennessee Valley Authority, consists of the area immediately around Norris Dam and immediately downstream from the dam on both sides of the Clinch. The western half of the reservation, which is largely undeveloped, is known as the River Bluff Small Wild Area. Norris Dam State Park consists of two sections along the