(a) In all instances where authorizations of appropriations for the acquisition of lands for the National Park System enacted prior to January 9, 1971, do not include provisions therefor, there are authorized to be appropriated such additional sums as may be necessary to provide for moving costs, relocation benefits, and other expenses incurred pursuant to the applicable provisions of the Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970 (Public Law 91–646; 84 Stat. 1894). There are also authorized to be appropriated not to exceed $8,400,000 in addition to those authorized in Public Law 92–272 (86 Stat. 120) to provide for such moving costs, relocation benefits, and other related expenses in connection with the acquisition of lands authorized by Public Law 92–272.

(b) Whenever an owner of property elects to retain a right of use and occupancy pursuant to any statute authorizing the acquisition of property for purposes of a unit of the National Park System, such owner shall be deemed to have waived any benefits under sections 4623, 4624, 4625, and 4626 of this title, and for the purposes of those sections such owner shall not be considered a displaced person as defined in section 4601(6) of this title.