Mont. Code Ann. tit. 25, ch. 24, Rule 13
Decorum
Rule 13 . Decorum.
(a) When the court convenes all persons in attendance in the courtroom shall rise until the judge has taken the bench.
(b) The judge of the court shall, when presiding in open court, wear judicial robes.
(c) All persons shall, when in the courtroom, wear appropriate clothing.