Mont. Code § 72-2-909
The secretary of state shall establish a registry system by which authorized persons may register in a central information center information regarding the execution of international wills, keeping that information in strictest confidence until the death of the maker and then making it available to any person desiring information about any will who presents a death certificate or other satisfactory evidence of the testator's death to the center. Information that may be received, preserved in confidence until death, and reported as indicated is limited to the name, social security or individual-identifying number established by law, address, and date and place of birth of the testator and the intended place of deposit or safekeeping of the instrument pending the death of the maker. The secretary of state, at the request of the authorized person, may cause the information that the secretary of state receives about the execution of any international will to be transmitted to the registry system of another jurisdiction as identified by the testator if that other registry system adheres to rules protecting the confidentiality of the information similar to those established in this state.
§ 72-2-909, MCA