Mont. Code Ann. § 20-6-314
A high school district may not be created and a high school district boundary may not be changed between the first day of January and the fourth Monday of August of any calendar year except when:
History: En. Sec. 1, Ch. 617, L. 1983; amd. Sec. 10, Ch. 22, L. 1997; amd. Sec. 2, Ch. 403, L. 1997; amd. Sec. 8, Ch. 237, L. 2001.