OregonLive.com | Army Corps of Engineers say 474 gallons of oil could have spilled into Columbia River OregonLive.com The Army Corps of Engineers reported late Wednesday that 474 gallons of oil is missing and could be in the Columbia River downstream of The Dalles Dam. Employees at the dam said the oil disappeared from a turbine that generates electricity from running ... US Army Corps of Engineers May Have Spilled More Than 470 Gallons of Oil Into the Columbia River |