Ashely Cox, river engineer with the U.S. Army Corps of Engineers St. Louis District talks with STEM students about how the Corps of Engineers uses Hydraulic Sediment Response modeling to address various problems on the river at the National Great Rivers Museum in Alton, Ill., during the Saturday Scholars program at Melvin Price Locks and Dam Feb. 25, 2012. (U.S. Army Corps of Engineers photo by Public Affairs Specialist Romanda Walker)