Mont. Code Ann. § 7-14-2825

No toll ferry must be established within 1 mile immediately above or below a regularly established ferry unless the situation of a town or village, the crossing of a public highway, or the intersection of some creek or ravine renders it necessary for public convenience. In addition to the public notice required, notice of intention to apply for authority to erect a toll ferry must be served upon the proprietor of the ferry already established, at least 10 days prior thereto, giving the time and place and grounds of such application.