National Park Service concessions management [electronic resource] : hearings before the Subcommittee on National Parks, Historic Preservation, and Recreation of the Committee on Energy and Natural Resources, United States Senate, One Hundred Seventh Congress, first session to review the National Park Service implementation of management policies and procedures to comply with the provisions of Titles I, II, III, IV, V, VI, VII, and VIII of the National Parks Omnibus Management Act of 1998, March 22, 2001, March 29, 2001.