English: Shoals are exposed along the Mississippi River near Vicksburg, MS on Aug. 22, 2012. The 2012 severe drought has affected current flow conditions in the Mississippi River and caused low water levels exposing shoals and potentially putting river traffic at risk for running aground. Barge movements on the Mississippi River are important to U.S. Agriculture for the transportation approximately 50 percent of U.S. grain; such as corn, soybean, wheat and rice. Though water levels are low, the Mississippi River is still open to transportation and the U.S. Department of Agriculture (USDA) continues to work with Federal partners to monitor conditions on this critical waterway for U.S. commodities. Photo by U.S. Army Corps of Engineers.