The Secretary is authorized to acquire lands, waters, and interests therein within the boundaries of the park by donation, purchase with donated or appropriated funds, or exchange: Provided, however, That the Secretary may not acquire lands within the Forked Lightning Ranch as depicted on the map from the owner of record of such lands as of May 1, 1990 , without the consent of such owner unless the Secretary determines that the lands are being used, or that there is an imminent threat that the lands will be used, for any purpose that is incompatible with the purposes of this Act. ( Pub. L. 101–313, title II, § 203 , June 27, 1990 , 104 Stat. 279 .) Editorial Notes References in Text This Act, referred to in text, is Pub. L. 101–313 , June 27, 1990 , 104 Stat. 272 , which enacted this subchapter, amended sections 410pp, 410pp–1, and 460uu–12 of this title, and enacted and repealed provisions listed in a Miscellaneous National Monuments table set out under section 320301 of Title 54 , National Park Service and Related Programs. For complete classification of this Act to the Code, see Tables.