An Analysis Of The Columbia And Snake River Anadromous Fish Runs

The history of the Columbia and Snake River anadromous fish runs since the first dams were built on these rivers is of significant interest to policy makers in the Pacific Northwest. The records of the fish passage have a story of their own to tell, and this paper attempts to shed some light on what has happened since the first dam was built and made operational in 1938. The focus of this study is directed toward the eight dams built on the Columbia River and Snake rivers between 1938 and 1975. The fish run records evaluated extend from 1938 to 1994. The study is divided into three parts. The first part deals with the impact of the Columbia River dams on fish runs. The second part deals with the impact of the Snake River dams on fish runs. And, the third part deals with the overall results of dam construction on these fish runs