Park Service authorities bills : hearing before the Subcommittee on Parks and Recreation of the Committee on Interior and Insular Affairs, United States Senate, Ninety-fourth Congress, second session, on S. 3430, a bill to amend the act approved August 18, 1970, providing for improvement in the administration of the National Park system by the Secretary of the Interior and clarifying authorities applicable to the National Park system, and for other purposes ; H.R. 13713, an act to provide for increases in appropriation ceilings and boundary changes in certain units of the National Park system, and for other purposes and similar measures encompassing 28 units of the National Park system: S. 91, S.1133, S. 1510, S.2182, S 2257, S. 2325, S. 2904, S. 2984, S. 3012, S. 3116, S. 3373, S. 3410, S. 3501, S. 3560, S. 3673, July 26, 1976.