Mont. Code Ann. § 72-3-311
Priority of determinations in contested cases
72-3-311 . Priority of determinations in contested cases. If a will is opposed by the petition for probate of a later will revoking the former, it shall be determined first whether the later will is entitled to probate, and if a will is opposed by a petition for a declaration of intestacy, it shall be determined first whether the will is entitled to probate.