Lake Oahe in winter, 2009
|Location||South Dakota, North Dakota|
|Coordinates||Coordinates: at Oahe Dam|
|Primary inflows||Missouri River, Cheyenne River, Moreau River, Grand River|
|Primary outflows||Missouri River|
|Basin countries||United States|
|Max. length||231 mi (372 km)|
|Surface area||370,000 acres (150,000 ha)|
|Max. depth||205 ft (62 m)|
|Water volume||23,500,000 acre·ft (29.0 km3)|
|Shore length1||2,250 mi (3,620 km)|
|Surface elevation||1,647 ft (502 m)|
1 Shore length is not a well-defined measure.
Lake Oahe (oh-WAH'-hee) is a large reservoir behind Oahe Dam on the Missouri River beginning in central South Dakota and continuing north into North Dakota in the United States. The lake has an area of 370,000 acres (1,500 km2) and a maximum depth of 205 ft (62 m). By volume, it is the fourth-largest reservoir in the US. Lake Oahe has a length of approximately 231 mi (372 km) and has a shoreline of 2,250 mi (3,620 km). 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.
Species of fish in the reservoir include walleye, northern pike, channel catfish, and smallmouth bass. Chinook Salmon, native to the Pacific Northwest, are artificially maintained in Lake Oahe and are a popular target for anglers. The lake also supports populations of the endangered pallid sturgeon.
Lake Oahe begins just north of 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. A map centered around Mobridge probably gives the best view of the extent 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 is now beneath Lake Oahe, about 9 miles west of Gettysburg.
Both the Cheyenne River Indian Reservation and the Standing Rock Indian Reservation cover much of the western shoreline of Lake Oahe. Two possible burial sites of Sitting Bull, a Sioux leader, are located along Lake Oahe. One is near Fort Yates, North Dakota, while the other is near Mobridge.
See also 
- "Oahe Dam & Lake". United States Army Corps of Engineers. Retrieved 2010-04-26.
- "Gavins Point Dam & Power Plant". United States Army Corps of Engineers. Retrieved 2010-04-26.
- "Corps Lakes Getaway: Oahe Dam/Lake Oahe". United States Army Corps of Engineers. Retrieved 2010-04-26.
- "2010 Lake Oahe Fishery Projections". South Dakota Department of Game, Fish and Parks. Retrieved 2010-04-26.
- "Chinook Salmon". Northern State University. Retrieved 2008-08-09.
- Barry, Dan. Restoring Dignity to Sitting Bull, Wherever He Is  The New York Times. January 28, 2007. (accessed 2010-04-26)