Minn. Stat. § 92.50
Subd. 1. Lease terms.
(a) The commissioner of natural resources may lease land under the commissioner's jurisdiction and control:
(c) The lease term may not exceed ten years except:
Subd. 2. Leases for tailings deposits.
The commissioner may grant leases and licenses to deposit tailings from any iron ore beneficiation plant in any public lake not exceeding 160 acres in area after holding a public hearing in the manner and under the procedure provided in Laws 1937, chapter 468, as amended and finding in pursuance of the hearing:
(b) that the proposed use will not result in pollution or sedimentation of any outlet stream.
The lease or license may not exceed a term of 25 years and must be subject to cancellation on three years' notice. The commissioner may further restrict use of the lake to safeguard the public interest, and may require that the lessee or licensee acquire suitable permits or easements from the owners of lands riparian to the lake. Money received from the leases or licenses must be deposited in the permanent school fund.