Quick search by citation:

16 U.S. Code § 228d - Acquisition of State of Arizona or local lands by donation or exchange; approval for transfer to United States of Indian trust lands

Notwithstanding any other provision of sections 228a to 228j of this title (1) land or interest in land owned by the State of Arizona or any political subdivision thereof may be acquired by the Secretary under sections 228a to 228j of this title only by donation or exchange and (2) no land or interest in land, which is held in trust for any Indian tribe or nation, may be transferred to the United States under sections 228a to 228j of this title or for purposes of sections 228a to 228j of this title except after approval by the governing body of the respective Indian tribe or nation.