Mont. Code Ann. § 16-3-304

Except as provided in 16-3-305, all licensed establishments wherein alcoholic beverages are sold, offered for sale, or given away at retail shall be closed each day between 2 a.m. and 8 a.m.; provided, however, that when any municipal incorporation has by ordinance further restricted the hours of sale of alcoholic beverages, then the sale of alcoholic beverages is prohibited within the limits of any such city or town during the time such sale is prohibited by this code and in addition thereto during the hours that it is prohibited by such ordinance. During such hours all persons except the alcoholic beverage licensee and employees of such licensed establishment shall be excluded from the licensed premises.