Any lands acquired by the Secretary of the Interior under the terms of this section and , if located within or adjacent to an existing wildlife refuge or reservation, immediately shall become a part of such refuge or reservation and shall be administered under the laws and regulations applicable thereto, and, if not so located, may be administered as a migratory-waterfowl management area, refuge, reservation, or breeding ground in accordance with the provisions of the Act of (), and Acts supplementary thereto.section 666d of this title60 Stat. 1080August 14, 19461946-08-14