| 1. |  | Barge entering Lock and Dam #15 | Mississippi River--Locks and Dams--Lock and Dam 15; Locks (Hydraulic engineering); Government Bridge (Rock Island, Ill.-Davenport, Iowa); Bridges; Swing bridges; Mississippi River; Rivers; Towboats; Barges; Boats; Riverboats; Rock Island (Ill.); Photographic prints | Photograph of a barge entering Lock and Dam #15 on the Mississippi River at Rock Island, Illinois. The swing span is open to allow the towboat and barge through the lock. |
