Minn. Stat. § 383C.23

On all highways under the jurisdiction of the county of St. Louis, if weight and load limitations are imposed by the county board, or the county engineer if so authorized by the board, in accordance with sections 163.02, subdivision 3 , and 169.87 , no exception shall be made to the weight or load limitations for any vehicles except (1) school buses and (2) public utility vehicles used under emergency conditions, and (3) other vehicles used in an emergency of any nature.