Lake Oahe Lake Oahe Lake Oahe (oh-WAH'-hee) is a large reservoir behind Oahe Dam on the Missouri River; it begins in central South Dakota and continues north into North Dakota in the United States. The lake has an area of and a maximum depth of . By volume, it is the fourth-largest reservoir in the US. Lake Oahe has a length of approximately and has a shoreline of . 51 recreation areas are located along Lake Oahe, and 1.5 million people visit the reservoir every year. The lake is named for the 1874 Oahe Indian Mission. Lake Oahe begins just north of
Norris Dam State Park State of Tennessee in 1953. The state developed the more modern west section of the park in the 1970s, and obtained control of the marina in 1986. The CCC-built area was listed on the National Register of Historic Places in 2014. The older east section of Norris Dam State Park has 19 rustic cabins, a 40-site campground, and a convention house known as the "Tea Room". The newer west section has 10 deluxe cabins, a 50-site campground, and a recreation center. The park offices are located in the west section. The marina is located just west of the dam. Both