Montana Constitution, Article VII
Section 3. Supreme court organization. (1) The supreme court consists of one chief justice and four justices, but the legislature may increase the number of justices from four to six. A majority shall join in and pronounce decisions, which must be in writing.
(2) A district judge shall be substituted for the chief justice or a justice in the event of disqualification or disability, and the opinion of the district judge sitting with the supreme court shall have the same effect as an opinion of a justice. 