Mich. Comp. Laws § 324.2105
If the department determines that it is in the best interests of the state to relinquish or convey to the United States under the laws of the United States any part or portion of the lands described in section 2104 in exchange for other lands of equal area or approximately equal value to be selected by the department from the unappropriated public lands in this state that belong to the United States and that may be relinquished or conveyed to the state by the United States under the laws of the United States, the department shall maintain a description of the lands belonging to the state that are to be relinquished or conveyed to the United States, and, upon making arrangements with the proper authorities of the United States, the department shall execute the proper conveyance to the United States of the lands to be relinquished or conveyed. This conveyance shall be void if the lands of an equal area or approximately equal value are not relinquished or conveyed by the United States to the state in lieu of the lands and in accordance with selections made by the department.
MCL 324.2105