A will of a nondomiciliary decedent that has been filed and not probated in a court in the domiciliary state may be proved for probate in this state by an authenticated certificate of its legal custodian that the copy introduced is a true copy and that the will has been filed and not submitted for probate in the court in the domiciliary state.
Nondomiciliary Decedent -- Will Filed And Not Probated In Domiciliary State
Mont. Code Ann. § 72-3-320, under Formal Testacy and Appointment Proceedings.
Mont. Code Ann. § 72-3-320