Montana Constitution, Article VI
Section 2. Election. (1) The governor, lieutenant governor, secretary of state, attorney general, superintendent of public instruction, and auditor shall be elected by the qualified electors at a general election provided by law.
(2) Each candidate for governor shall file jointly with a candidate for lieutenant governor in primary elections, or so otherwise comply with nomination procedures provided by law that the offices of governor and lieutenant governor are voted upon together in primary and general elections.