Appalachian Power Company constructed Smith Mountain and Leesville Dams on the Roanoke River between 1960 and 1963 to generate hydroelectric energy. Between the dams, the river rose to form 3,400-acre Leesville Lake. West of Smith Mountain Dam, the Blackwater and Roanoke Rivers covered 20,600 acres that had primarily been farmland, forming Smith Mountain Lake. On 7 March 1966, Smith Mountain Lake's water level first reached “full pond” (795 feet above sea level). The largest lake wholly within Virginia, it became a popular residential area and recreational destination. The two lakes have a combined shoreline of 88 miles in Pittsylvania County.