 The lake was created in 1920 when the United States Army Corps of Engineers used material dredged from the Anacostia River to create Kingman Island.The Corps of Engineers largely blocked the flow of the Anacostia River to the west of Kingman Island, creating the lake (although some water is permitted to enter the lake to prevent it from completely evaporating and to refresh its waters).Kingman Lake is currently managed by the National Park Service.