N.D. Cent. Code § 24-17-12

The director shall enforce the provisions of this chapter and the rules adopted by the director through the remedy of injunction or other appropriate legal proceedings, and may not act except through such proceedings, except as set forth in section 24-17-11. Neither the director nor any other agency nor political subdivision of this state may, by plantings, obstruct the view or in any other way interfere with the effectiveness of any sign legally in place under the provisions of this chapter and the rules adopted by the director.