The Mitchell Act was enacted in 1938 to provide for conservation of anadromous (salmon and steelhead) fishery resources of the Columbia River. The program has evolved into three primary components:

• Operation of 17 fish hatcheries (from a high of 25 hatcheries and major rearing ponds) with the release of between 50 and 60 million juvenile anadromous fish in Oregon, Washington, and Idaho.
• Construction, operation and maintenance of more than 700 fish screens at irrigation diversions to protect juvenile salmon and steelhead in Oregon, Washington and Idaho.
• Ongoing operations and maintenance of 90 fishways enhancing adult fish passage to nearly 2,000 miles of stream habitat in all three states.

Historically, production from the program has provided fish for tribal treaty fisheries in the Columbia River, and for ocean and in-river recreational and commercial fisheries. Renegotiation of the Columbia River Fish Management Plan per U.S. v. Oregon includes this program. More recently, hatchery programs funded through the Mitchell Act are conserving genetic resources for the purposes of the Endangered Species Act (ESA) and reintroducing salmon into parts of their former range.

With application of the ESA throughout the Columbia River Basin, substantial changes have been, and will continue to be required of the Mitchell Act Program. Overall hatchery production has been reduced from more than 100 million to less than 60 million fish. An environmental impact statement (EIS) is being prepared to evaluate the effects of the funding and operation of Mitchell Act hatcheries. Hatchery reprogramming efforts are under way to preserve genetic resources and revitalize restricted fishing opportunities by creating selective fisheries for marked hatchery fish, and terminal fisheries on hatchery-only fish.