Mont. Code Ann. § 20-6-509

Whenever it is in the best interest of the pupils affected, the trustees of any district may close any school of the district, except that a junior high school may be closed only by joint action of the trustees of the elementary district and the high school district in which the school is located. Whenever the trustees of a district close a school of the district, they shall provide the pupils of the closed school with transportation and tuition, if required, to other schools in accordance with the provisions of this title.