Yankton Sioux Tribe and Santee Sioux Tribe of Nebraska Development Trust Fund Act

Yankton Sioux Tribe and Santee Sioux Tribe of Nebraska Development Trust Fund Act - Establishes in the Treasury the Yankton Sioux Tribe Development Trust Fund and the Santee Sioux Tribe of Nebraska Development Trust Fund. Directs the Secretary of the Treasury to: (1) deposit a specified amount into each Fund; (2) invest such amounts and deposit resulting interest in the Funds; and (3) withdraw the aggregate amount of interest deposited into the Funds each fiscal year and transfer that amount to the Secretary of the Interior to use for making payments to the Yankton Sioux Tribe and the Santee Sioux Tribe, as requested by each Tribe pursuant to tribal resolution, for carrying out projects and programs under each Tribe's Tribal Plan. Permits each Tribe to enter into an agreement under which it pledges future payments as security for a loan or other financial transaction, but only in connection with the purchase of land or other capital assets, and only for an amount less than 40 percent of any payment for that year.

Directs the tribal council of each Tribe to prepare a Tribal Plan for using payments for carrying out projects and programs to promote: (1) economic development; (2) infrastructure development; or (3) the educational, health, recreational, and social welfare objectives of the Tribe and its members.

Prohibits any payment made to either Tribe pursuant to this Act from: (1) resulting in the reduction or denial of any service or program to which the Tribe or any member of the Tribe is otherwise entitled because of federally recognized status; (2) being subject to any Federal or State income tax; or (3) affecting Pick-Sloan Missouri River Basin power rates.

Authorizes appropriations.