Minn. Stat. § 383C.232: STATE AND OTHER ROAD NUMBERS.

The St. Louis County Board may by resolution provide a suitable method of numbering or otherwise describing the state roads, county roads and town roads within its boundaries, erecting and maintaining an adequate system of road signs thereon and preparing and causing to be circulated an accurate road map of said county, showing thereon such of said roads as said county board shall deem in the public interest. The county board may distribute said road maps free of charge, or may sell the same at cost to civic organizations, automobile clubs or other parties desiring to purchase same for circulation. The expense of any and all such acts and things herein authorized may be paid for by said county board out of the county road and bridge fund and any collections made by said board for any such maps so sold shall be credited to said fund.