Three Affiliated Tribes and Standing Rock Sioux Tribe Equitable Compensation Act

Three Affiliated Tribes and Standing Rock Sioux Tribe Equitable Compensation Act - Declares that: (1) the Three Affiliated Tribes (TAT) (the Mandan, Hidatsa, and Arikara Tribes that reside on the Fort Berthold Indian Reservation) are entitled to additional financial compensation from amounts deposited to a TAT Recovery Fund for the taking of reservation lands for the site of the Garrison Dam and Reservoir; and (2) the Standing Rock Sioux Tribe (SRST) (members of the Great Sioux Nation that reside on the Standing Rock Indian Reservation) is entitled to additional financial compensation from amounts deposited to a SRST Economic Recovery Fund for the taking of reservation lands as the site for the Oahe Dam and Reservoir.

Establishes such Funds. Directs the Secretary of the Treasury to deposit into each Fund 25 percent of the receipts from deposits to the Treasury for the preceding fiscal year from the integrated programs of the Eastern Division of the Pick-Sloan Missouri River Basin Project administered by the Western Area Power Administration, subject to certain limitations. Authorizes appropriations to each Fund. Makes available only the interest on the moneys in each Fund for use by the Secretary of the Interior in making payments to the SRST and TAT for use for educational, social welfare, economic development, and other programs. Specifies that: (1) no payments pursuant to this Act shall result in the reduction or denial of any Federal services or programs to which the TAT or SRST, or any of their members, are otherwise entitled to because of their status as federally recognized Indian tribes or members pursuant to Federal law; (2) no such payments shall be subject to Federal or State income tax, or affect power rates; and (3) no part of any moneys in either Fund shall be distributed to any TAT or SRST member on a per capita basis.

Authorizes the Secretary to develop irrigation within the boundaries of the Standing Rock Indian Reservation, subject to a finding by the Secretary of irrigability of the lands to receive water. Authorizes appropriations.

Declares certain Federal lands in North Dakota to be held in trust by the United States for the TAT as part of the Fort Berthold Reservation.

Directs the Secretary of the Army to transfer administrative jurisdiction to the Secretary of Interior (Secretary) over certain nontribal Federal lands acquired from individual Indian and non-Indian owners for the Garrison Dam Project (Project).

Requires the Secretary to offer a right of first refusal to such individual owners, their heirs, or assignees, for a maximum one-year period after notification of their rights, to purchase at fair market value any land the owner conveyed to the United States for the Project.

Requires the Secretary to declare such lands to be held in trust for the TAT as part of the Fort Berthold Indian Reservation if the former owner, or the heirs or assignees, refuses or fails to exercise the right to repurchase the lands.

Prohibits the sale of lands purchased from the Secretary by former owners, their heirs, or assignees under this Act within five years of such purchase unless the TAT has been afforded a right of first refusal to purchase them.

Reserves to the United States the perpetual right, power, privilege, and easement permanently to overflow, flood, submerge, saturate, percolate, and erode such lands in connection with the operation and maintenance of the Garrison Dam Project, and the continuing right to remove any detrimental brush, debris, and natural obstructions.

Prohibits, without the Secretary of the Army's approval, the construction or maintenance of structures on such lands, or excavation or landfill placement.

Declares that nothing in this Act shall deprive any person of any right-of-way, leasehold, or other right, interest, or claim which such person may have in the lands before the enactment of this Act.

Declares that all rights, title, and interest of the United States in certain improvements and recreation facilities are held in trust by the United States for the TAT.

Declares that all right, title, and interest of the United States in certain Federal lands and underlying Federal minerals, acquired from the SRST for the Oahe Dam and Reservoir Project (Project), are held in trust by the United States for the SRST as part of the Standing Rock Indian Reservation.

Directs the Secretary of the Army to transfer administrative jurisdiction to the Secretary of the Interior over specified Federal lands acquired for such Project from individual Indian and non-Indian owners.

Requires the Secretary to offer a right of first refusal to such individual owners, their heirs, or assignees, for a maximum one-year period after notification of their rights, to purchase at fair market value any land the owner conveyed to the United States for the Project.

Requires the Secretary to declare such lands to be held in trust for the SRST as part of the Standing Rock Indian Reservation if such owner, or the heirs or assigns, refuses or fails to exercise the right to repurchase the lands.

Prohibits the sale of such lands by former owners, or their heirs or assigns under this Act within five years of such purchase unless the SRST has been afforded a right of first refusal to purchase them.

Reserves to the United States the perpetual right, power, privilege, and easement permanently to overflow, flood, submerge, saturate, percolate, and erode such lands in connection with the operation and maintenance of the Project, and the continuing right to remove any detrimental brush, debris, and natural obstructions.

Prohibits, without approval of the Secretary of the Army, the construction or maintenance of structures on such lands, or excavation or landfill placement.

Declares that nothing in this Act shall deprive any person of any right-of-way, leasehold, or other right, interest, or claim which such person may have in such lands before enactment of this Act.

Declares that all right, title, and interest of the United States in certain improvements and recreation facilities in North Dakota (except for the Indian Memorial Recreation Area and the Grand River Fish Spawning Station, unless specified conditions are met) are held in trust by the United States for the SRST.

Requires that Oahe Dam and Lake Project lands transferred by this Act which were formerly designated as mitigation lands for fish and wildlife conservation purposes shall be included in any subsequent determination of the Corps of Engineers' (Corps) compliance with certain Federal law.

Directs the SRST to use its best efforts to conduct fish and wildlife conservation and mitigation on such lands.

Denies South Dakota any claim, right, or cause of action under Federal law to compel designation of additional lands currently under Corps jurisdiction for fish and wildlife conservation purposes in lieu of the lands transferred by this Act.

Authorizes appropriations.