Covering approximately 750 sq miles, it is the second-largest freshwater lake in the continental United States. Its greatest depth is 24 feet, but the water is so shallow in most places that birds can be seen wading a mile from shore. A lighted pier at Lock 7 (Hwys 441 & 70) provides day and night fishing. A levee surrounds the entire lake and protects adjacent rich lands from overflow. Recreational facilities surround the lake.