Minn. Stat. § 219.52: WARNING SIGN; REPORTING CLEARANCE VIOLATIONS.

If a structure is nearer the track than as provided by sections 219.45 to 219.53, the commissioner of transportation shall provide for warning signs to be placed on it of a design and type as the commissioner considers proper unless the commissioner determines a sign is unnecessary. Railroad inspectors of the Department of Labor and Industry shall report to the commissioner and attorney general any violation of sections 219.45 to 219.53 of which they may obtain knowledge.