The dam was authorized as Foster Creek Dam and Powerhouse for power generation and irrigation by the
River and Harbor Act of 1946. The
River and Harbor Act of 1948 renamed the project
Chief Joseph Dam in honor of the
Nez Perce chief who spent his last years in exile on the
Colville Indian Reservation. Like the immediate upstream and downstream dams, Chief Joseph does not have any form of
fish ladder system installed. Therefore, like
Grand Coulee and
Wells dam, upstream and downstream respectively, Chief Joseph does not allow the passage of migrating fish. Construction began in 1950, with the main dam and intake structure completed in 1955. Installation of the initial generating units was started in 1958 and completed in 1961. Ten additional turbines were installed between 1973 and 1979, and the dam and lake were raised , boosting the capacity to , making Chief Joseph Dam the second largest hydroelectric power producer in the United States. The vast majority (80% on average) of the power from Chief Joseph dam is sent to the Everett area of western
Snohomish county via the
Bonneville Snohomish substation. However, power produced at the dam is not only used in Washington, but also in Oregon, Montana, Idaho, California, Wyoming, Utah and Nevada. == Type ==