Subd. 1.

The commissioner of natural resources may designate any lands belonging to the state or in which the state has an interest as mining units and may rearrange or modify such mining units from time to time, subject to the limitations herein prescribed. No mining unit shall contain lands belonging to more than one permanent trust fund. Lands which have been sold by the state and are in use as part of the site of a plant for the production of taconite concentrates shall not be designated as mining units. Each mining unit shall consist of a contiguous tract not exceeding 80 acres in area except as follows:

1. (1) An area not exceeding 90 acres consisting of or including one or more government lots or fractional or oversized subdivisions according to the government survey may be included in one mining unit.
2. (2) An area of any size which has been covered by a state mining lease or contract heretofore issued and heretofore or hereafter terminated may be included in one mining unit.
3. (3) An area of any size within the bed of any public waters belonging to the state may be included in one mining unit.

Subd. 2.

The commissioner shall prepare and keep on file in the office of the division of lands and minerals of the department of natural resources and at such other places as the commissioner may direct a list of the mining units designated hereunder, giving the descriptions thereof and such other information as the commissioner deems necessary. In case the commissioner shall prescribe special conditions to be included in a prospecting permit or lease for any mining unit as authorized by law, a statement of such conditions shall be included with the designation of such unit in the list.

Subd. 3.

Except as otherwise expressly provided by law, each prospecting permit or mining lease shall cover only one entire mining unit designated as herein provided, and the designation of a mining unit in force at the time an application for a prospecting permit therefor is received by the commissioner according to law shall govern and shall remain unchanged for the purposes of such permit or any lease issued pursuant thereto.