Mont. Code § 85-2-601
The legislature, noting that appropriations have been claimed, that applications have been filed for, and that there is further widespread interest in making substantial appropriations of water in the Yellowstone River basin, finds that these appropriations threaten the depletion of Montana's water resources to the significant detriment of existing and projected agricultural, municipal, recreational, and other uses and of wildlife and aquatic habitat. The legislature further finds that these appropriations foreclose the options to the people of this state to utilize water for other future beneficial purposes, including municipal water supplies, irrigation systems, and minimum flows for the protection of existing rights and aquatic life. The legislature, pursuant to its mandate and authority under Article IX of the Montana constitution, declares that it is the policy of this state that before these proposed appropriations are acted upon, existing rights to water in the Yellowstone basin must be accurately determined for their protection and that reservations of water within the basin must be established as rapidly as possible for the preservation and protection of existing and future beneficial uses.
§ 85-2-601, MCA