Mont. Code Ann. § 25-9-503

A copy of any foreign judgment authenticated in accordance with an act of congress or the statutes of this state may be filed in the office of the clerk of any district court of this state. The clerk shall treat the foreign judgment in the same manner as a judgment of a district court of this state. A judgment so filed has the same effect and is subject to the same procedures, defenses, and proceedings for reopening, vacating, or staying as a judgment of a district court of this state and may be enforced or satisfied in like manner.