Mont. Code Ann. § 39-31-207
(1) The board or an agent of the board shall investigate the petition and, if it has reasonable cause to believe that a question of representation exists, it shall provide for an appropriate hearing upon due notice whenever, in accordance with such rules as may be prescribed by the board, a petition has been filed:
(a) by an employee or group of employees or any labor organization acting in their behalf alleging that 30% of the employees:
History: En. Sec. 6, Ch. 441, L. 1973; amd. Sec. 1, Ch. 136, L. 1975; R.C.M. 1947, 59-1606(part).