54 U.S.C. § 100101 Promotion and regulation
(a) In General.—The Secretary, acting through the Director of the National Park Service, shall promote and regulate the use of the National Park System by means and measures that conform to the fundamental purpose of the System units, which purpose is to conserve the scenery, natural and historic objects, and wild life in the System units and to provide for the enjoyment of the scenery, natural and historic objects, and wild life in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.
(b) Declarations.—(1) 1970 declarations.—Congress declares that—(A) the National Park System, which began with establishment of Yellowstone National Park in 1872, has since grown to include superlative natural, historic, and recreation areas in every major region of the United States and its territories and possessions; (B) these areas, though distinct in character, are united through their interrelated purposes and resources into one National Park System as cumulative expressions of a single national heritage; (C) individually and collectively, these areas derive increased national dignity and recognition of their superb environmental quality through their inclusion jointly with each other in one System preserved and managed for the benefit and inspiration of all the people of the United States; and (D) it is the purpose of this division to include all these areas in the System and to clarify the authorities applicable to the System. (2) 1978 reaffirmation.—Congress reaffirms, declares, and directs that the promotion and regulation of the various System units shall be consistent with and founded in the purpose established by subsection (a), to the common benefit of all the people of the United States. The authorization of activities shall be construed and the protection, management, and administration of the System units shall be conducted in light of the high public value and integrity of the System and shall not be exercised in derogation of the values and purposes for which the System units have been established, except as directly and specifically provided by Congress.