Minn. Stat. § 93.02: INSTRUMENTS TRANSFERRING INTEREST; RESERVATION.

When any such land is sold, granted, conveyed, or transferred in any way the certificate of sale, patent, or other instrument of transfer shall state that the sale, grant, conveyance, or transfer does not include any right, title, or interest in or to any iron, coal, copper, gold, or other valuable minerals which may be in or upon the land and that all these minerals are reserved by the state for its own use; but no instrument shall be effective to transfer any right, title, or interest in or to any such minerals, notwithstanding the failure of the proper officer to insert such statement.