Levee Repair Contractors add rock to the face of a levee near Yankton, S.D., to repair erosion, June 16, 2011. Currents from the Missouri River were eroding the underside of the levee, causing the rock face to fall away due to record releases from the Oahe and Gavins Point Dams. SHARE: Download: Full Size (1.18 MB) Credit: Air Force Tech. Sgt. Quinton Young VIRIN: 110616-F-UL435-101.JPG Photo Gallery