Mont. Code Ann. § 85-6-107

An incorporated water users' association that is sustaining and responsible for the operations of a works is solely liable for any court action which may be brought against it for any injury or damages occurring on the works caused by a failure to maintain safe working and operating conditions. The state of Montana is not liable for injury to a person or property that occurs on a works as a result of a failure by a water users' association to maintain the works in a safe working and operating condition.