Mont. Code Ann. § 16-4-422

Except as provided in 16-3-305, restaurants licensed pursuant to 16-4-420 in which beer and wine are sold, offered for sale, or given away at retail may not serve beer and wine between the hours of 11 p.m. and 11 a.m. However, if an incorporated city or town has by ordinance further restricted the hours of sale of beer and wine, then the sale of beer and wine in restaurants licensed to sell beer and wine, pursuant to 16-4-420, is prohibited within the limits of the city or town during the time that the sale is prohibited by this section and in addition to the hours that the sale is prohibited by ordinance.