In this Dec. 18, 2012 photograph, the U.S. Army Corps of Engineers towboat and inspection vessel, Motor Vessel Mississippi IV, sits in a permanent dry dock as part of the Lower Mississi

 

              In this Dec. 18, 2012 photograph, the U.S. Army Corps of Engineers towboat and inspection vessel, Motor Vessel Mississippi IV, sits in a permanent dry dock as part of the Lower Mississi
In this Dec. 18, 2012 photograph, the U.S. Army Corps of Engineers towboat and inspection vessel, Motor Vessel Mississippi IV, sits in a permanent dry dock as part of the Lower Mississippi River Museum in Vicksburg, Miss. The museum provides visitors with a extensive look at life surrounding the Mississippi River through several centuries by way of its interactive and static displays. Visitors also have the opportunity to tour aboard the vessel and see how crews worked and lived on the towboats used by the Corps of Engineers. (AP Photo/Rogelio V. Solis)