 In April 1964 , the U.S. Fish and Wildlife Service ( FWS ) released its report on the project . Though only a part of the larger Department of the Interior study , the FWS report came down strongly opposed to the dam on the grounds that it would irrevocably destroy the Yukon Flats , a critical waterfowl breeding ground . In January 1965 , the Bureau of Land Management set aside almost 9 @,@ 000 @,@ 000 acres ( 3 @,@ 600 @,@ 000 ha ) of land for construction of the dam and reservoir . It was a typical process that had been done for other dam projects several times before , but the amount of land to be set aside generated several months of hearings before the decision . 
