Mont. Code § 85-2-419
It is the declared policy of the state in 85-1-101 to encourage the conservation and full use of water. Consistent with this policy, holders of appropriation rights who salvage water may retain the right to the salvaged water for beneficial use. Except for a short-term lease pursuant to 85-2-410, any use of the right to salvaged water for any purpose or in any place other than that associated with the original appropriation right must be approved by the department as a change in appropriation right in accordance with 85-2-402 and 85-2-436, if applicable. Sale of the right to salvaged water must also be in accordance with 85-2-403, and the lease of the right to salvaged water must be in accordance with 85-2-408, 85-2-410, or 85-2-436.
§ 85-2-419, MCA