Gavins Point Dam is a hydroelectric dam on the Missouri River in the U.S. states of Nebraska and South Dakota. Built from 1952 to 1957, it impounds Lewis and Clark Lake. The dam is on the Nebraska-South Dakota border, west of Yankton, South Dakota. During the 2011 Missouri River Flood the dam was damaged by debris and a significant portion of rocks were dislodged from its upstream side. The U.S. Army Corps of Engineers soon began repairs the dam and its spillway gates.