Montana Title 7. Local Government § 7-2-4714. Filing of annexation order

(1) The clerk or other officer performing the duties of the clerk of the governing body of a municipality shall promptly make and certify under the seal of the municipal corporation a copy of the record so entered upon the minutes, which document shall be filed with the clerk of the county in which the municipality to which the territory or territories are sought to be annexed is situated.

(2) From and after the date of filing the document in the office of the county clerk or the effective date of the ordinance, whichever is later, the annexation of the territory or territories shall be complete. Thenceforth such annexed territory or territories shall be a part of the municipal corporation and the city or town to which the annexation is made has the power to pass all necessary ordinances pertaining thereto.