Mont. Code § 13-19-101
The purpose of this chapter is to provide the option of and procedures for conducting certain specified elections as mail ballot elections. The provisions of this chapter recognize that sound public policy concerning the conduct of elections often requires the balancing of various elements of the public interest that are sometimes in conflict. Among these factors are the public's interest in fair and accurate elections, the election of those who will govern or represent, and cost-effective administration of all functions of government, including the conduct of elections. The provisions of this chapter further recognize that when these and other factors are balanced, the conduct of elections by mail ballot is potentially the most desirable of the available options in certain circumstances.
§ 13-19-101, MCA