Mont. Code Ann. § 7-14-2824

The owner of the land on either bank of the waters to be crossed, with the owner of the land on the left bank descending given preference over the owner of the land on the right bank, is entitled to preference in procuring authority to construct a ferry. Whenever the owners of the banks do not apply for such authority within a reasonable time after the necessity therefor arises, the board of commissioners may grant authority to another.