Lake Sakakawea is a large reservoir in the north central United States, impounded in 1953 by Garrison Dam, a U.S. Army Corps of Engineers dam located in the Missouri River basin in central North Dakota. Named for the Shoshone-Hidatsa woman Sakakawea (who accompanied the Lewis and Clark Expedition), it is the largest man-made lake located entirely within North Dakota, the second largest in the United States by area after Lake Oahe, and the third largest in the United States by volume, after Lake Mead and Lake Powell.
The lake is located about from the state capital of Bismarck; the distance by the Missouri River is about . The lake's width averages between , with a maximum of at Van Hook Arm. Lake Sakakawea marks the maximum southwest extent of glaciation during the ice age. The lake is located within the counties of: Dunn, McKenzie, McLean, Mercer, Mountrail, and Williams.
The reservoir was created by construction of Garrison Dam, part of a flood control and hydroelectric power generation project named the Pick-Sloan Project along the Missouri river.
Garrison dam was completed in 1956. It is the second (and largest) of six main-stem dams on the Missouri River built and managed by the U.S. Army Corps of Engineers for flood control, hydroelectric power, navigation, and irrigation.
The creation of the lake displaced members of the Fort Berthold Indian Reservation from their villages of Van Hook and (Old) Sanish, which were inundated by creation of the lake. They relocated and founded the villages of New Town, White Shield, and Mandaree. Elbowoods was covered by the water, as was the original town site for Sanish to the northwest of New Town. But only a small portion of the Van Hook town site has ever been under water, the area near the old railroad tracks and elevators on the very south edge of the original town. The remainder of the Van Hook town site including the original Main Street and the residential areas to the north have not been underwater.