The U.S. Army Corps of Engineers owns and operates more than 650 dams across the country. Washington not only generates hydro power but plays a major role in what's in the water. Mary Cochran takes us to Lower Granite Dam. Includes sound bites from Mike Halter, Supervisory Fisheries Biologist, USACE, Doug Marsh, Research Fisheries Biologist, and Fred Mensik, Wash., Department of Fish and Wildlife.