Mont. Code Ann. § 81-22-108

The provisions of Title 30, chapter 14, part 2, relating to monopoly in the purchase or sale of products in general use are hereby expressly made applicable to all persons engaged in the business of buying milk, cream, or butterfat for the purpose of manufacture and those who shall violate any of the provisions of said sections. All milk, cream, butterfat, manufactured dairy products, or products made in the semblance or imitation of manufactured dairy products are hereby declared to be commodities and products in general use within the meaning of the sections aforesaid.