Montana Title 60. Highways and Transportation § 60-7-201. Grazing livestock on highway unlawful

(1) a state highway running through cultivated areas or a part of the fenced right-of-way of a state highway if in either case the highway has been designated by agreement between the transportation commission and the secretary of transportation as a part of the national system of interstate and defense highways; or

(2) a state highway designated by agreement between the transportation commission and the secretary of transportation as a part of the federal-aid primary system, except as provided in 60-7-202.