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, 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.