For a period of 30 days after publication in the Federal Register of a notice of classification for disposal, the classification shall be subject to the exercise of supervisory authority by the Secretary of the Interior for the purpose of administrative review. If, 30 days from date of publication, the Secretary has neither on his own motion, on motion of any protestant or the State Director exercised supervisory authority for review, the classification shall become the final order of the Secretary. The exercise of supervisory authority by the Secretary shall automatically vacate the classification and reinstate the proposed classification together with its segregative effect. In this event the final departmental decision shall be issued by the Secretary and published in the Federal Register.