Manhattan Project National Historical Park Act

Manhattan Project National Historical Park Act - Establishes the Manhattan Project National Historical Park as a unit of the National Park System, which may be composed of specified facilities, lands, or interests in one or more eligible areas or parts of such areas in Oak Ridge, Tennessee; Los Alamos, New Mexico; and Hanford, Washington.

Directs the Secretary of the Interior (the Secretary) and the Secretary of Energy (DOE) to enter into an agreement to govern their respective roles in administering the facilities, lands, or interests in land under the DOE's jurisdiction to be included in the Park.

Adds to the Park lands, interests in land, or facilities within the eligible areas which are acquired by the Secretary or are included in an amendment to the agreement.

Requires the Secretary to develop a general management plan for the Park.

Authorizes the Secretary to: (1) provide interpretive tours of historically significant Manhattan Project sites and resources in Tennessee, New Mexico, and Washington state that are located outside the boundary of the Park; and (2) enter into one or more agreements with the head of a federal agency to provide public access to, and management, interpretation, and historic preservation of, historically significant Project resources under the agency's control.

Manhattan Project National Historical Park Act - (Sec. 5) Establishes the Manhattan Project National Historical Park in the states of Tennessee, New Mexico, and Washington, as a unit of the National Park System.

Bars the establishment of the Park until: (1) sufficient land or interests in land have been acquired from among specified facilities, lands, or interests in one or more eligible areas or parts of such areas in Oak Ridge, Tennessee, Los Alamos, New Mexico, and Hanford, Washington; or (2) the Secretary of the Interior (the Secretary in this Act) has entered into an agreement with the Secretary of Energy (DOE) that meets the following criteria.

(Sec. 6) Directs the Secretary and the Secretary of Energy to enter into an agreement to govern their respective roles in administering the facilities, lands, or interests in land under DOE administrative jurisdiction that are to be included in the Park.

Requires any such agreement to require the Secretary to: (1) have decisionmaking authority for the content of historic interpretation of the Manhattan Project for purposes of administering the Park, and (2) ensure that the agreement provides an appropriate role for the National Park Service (NPS) in the preservation of the historic resources covered by the agreement.

Requires any such agreement to provide that the Secretary of Energy: (1) shall ensure that the agreement protects public safety, national security, and other aspects of the ongoing mission of DOE at the Los Alamos National Laboratory, Hanford Site, and Oak Ridge Reservation; (2) may consult with and provide historical information to the Secretary concerning the Manhattan Project; and (3) shall retain responsibility for any environmental remediation and structural safety that may be necessary in or around the facilities, land, or interests governed by the agreement.

(Sec. 7) Direts the Secretary to consult with interested state, county, and local officials, organizations and interested members of the public: (1) before executing any such agreement; and (2) in developing the general management plan.

(Sec. 8) Requires the Secretary to develop a general management plan for the Park.

Authorizes the Secretary to provide interpretive tours of historically significant Manhattan Project sites and resources in Tennessee, New Mexico, and Washington state that are located outside the boundary of the Park.

Permits the Secretary to acquire land and interests within the eligible areas only by: (1) transfer of administrative jurisdiction from DOE by agreement between the Secretary and the Secretary of Energy; or (2) purchase from willing sellers, donation, or exchange.

Permits the Secretary to acquire lands or interests in the vicinity of the Park for visitor and administrative facilities.

Authorizes the Secretary to enter into one or more agreements with the head of a federal agency to provide public access to, and management, interpretation, and historic preservation of, historically significant Project resources under the agency's control.

Allows the Secretary to accept donations from, and enter into cooperative agreements with, state, local, and tribal governments, organizations, or individuals, to further the purposes of such an agreement.