Stockwater is one of Montana’s oldest water uses and is critical to the continued survival of a Montana livestock industry. Before the Montana Water Use Act of July 1, 1973, livestock water rights belonged to whomever owned and watered livestock on a customary range. The person did not need to own the land or file a claim. The right became private property as soon as the livestock drank water. The right was for exactly as much as the herd needed to drink and no more.

Livestock water rights were never adequately addressed in the Montana Water Use Act, which focused on irrigation, wells, an...