Mich. Comp. Laws § 120.28

Sec. 28. The port commission of each port district shall have full power and authority to lease the harbor area belonging to the state of Michigan situated within such port district, to the highest bidder upon such terms and conditions as shall conform to the provisions of this act and to the comprehensive scheme of harbor improvement as herein later provided. Every such lease shall provide that the rental thereunder shall be payable to the county treasurer wherein such port district is situated for the use of such port district and to go into a special fund hereinafter provided for: Provided, That where the port district covers 2 or more counties such rents shall be paid to the county treasurer designated by the port commission.