Oxbow lake is a crescent-shaped lake that forms when a river channel is cut off from the main stream. Such a lake forms when a river changes its course to a more direct path to the sea. The river leaves deposits of earth at either end of the curve, and these deposits eventually separate it from the main stream. Many oxbow lakes are shallow. They may become filled with sediments from river floods and decayed vegetation, and so disappear. Many oxbow lakes are found in Louisiana, Arkansas, and Mississippi along the Mississippi River and some of its slow-moving branches. 
