Montana Constitution, Article XIII
Section 1. Nonmunicipal corporations. (1) Corporate charters shall be granted, modified, or dissolved only pursuant to general law.
(2) The legislature shall provide protection and education for the people against harmful and unfair practices by either foreign or domestic corporations, individuals, or associations.
(3) The legislature shall pass no law retrospective in its operations which imposes on the people a new liability in respect to transactions or considerations already passed.