A North Dakota Air National Guard CH-47 Chinook helicopter drops several one-ton sandbags. A North Dakota Air National Guard CH-47 Chinook helicopter drops several one-ton sandbags onto the spillway of the Clausen Springs Dam near Kathryn, N.D., on April 15, 2009. The sandbags will help divert water away from an area of the dam that is being eroded by rising water, which also threatens to flood a local creek. SHARE: Download: Full Size (0.03 MB) Credit: VIRIN: 431913-S-FFP56-152.jpg Photo Gallery