Water flows under open gates and down the spillway during a free-overflow spill test at Detroit Dam on the North Santiam River April 11. Juvenile spring Chinook salmon and winter steelhead prefer to swim near the surface of reservoirs during their downriver migration from their spawning grounds to the sea; the Corps is testing water management operations like this to determine the best ways to increase passage and survival of these endangered species. For more information about our efforts in the Willamette Basin, visit http://go.usa.gov/T5JF