(1) Within 30 days after the merger or consolidation plan has been adopted, documents of merger or consolidation setting forth the plan and the manner of adoption thereof shall be signed by the president or vice-president and by the secretary or assistant secretary of each association merging or consolidating and filed with the clerk and recorder of the county in which the principal office of the new or surviving association is located, if the office is in Montana, and with the Montana secretary of state.
(2) If the new or surviving association has its principal office in Montana, the merger or consolidation becomes effective as of the date of filing with the Montana secretary of state. If its principal office is outside the state of Montana, the merger or consolidation becomes effective upon full compliance with the laws of the state in which its principal office is located.