For the purpose of irrigation and reclamation of arid lands, for controlling floods, improving navigation, regulating the flow of the South Fork of the Flathead River, for the generation of electric energy, and for other beneficial uses primarily in the State of Montana but also in downstream areas, the Secretary of the Interior is authorized and directed to proceed as soon as practicable with the construction, operation, and maintenance of the proposed Hungry Horse Dam (including facilities for generating electric energy) on the South Fork of the Flathead River, Flathead County, Montana, to such a height as may be necessary to impound not less than one million acre-feet of water. The Hungry Horse project shall be subject to the Federal reclamation laws (Act of June 17, 1902 (32 Stat. 388), and Acts amendatory thereof or supplementary thereto).

The Secretary of the Interior is authorized to complete, as soon as the necessary additional material is available, the construction of the Hungry Horse Dam so as to provide a storage reservoir of the maximum usable and feasible capacity.