Mont. Code § 85-7-2105
Whenever the board of commissioners has provided for the payment of any indebtedness of the district by levy of a special tax or assessment and thereafter makes provision for the payment of said indebtedness by the issuance of bonds, said board may cancel any portion or all of said levy theretofore made to raise funds to pay said indebtedness. Whenever said board has provided for the payment of any indebtedness of the district by the authorization of bonds and the levy of a special tax or assessment to pay the principal of and interest on said bonds and thereafter cancels said issue of bonds as provided for in 85-7-2025, said board may cancel any portion or all of said levy theretofore made to raise funds to pay the principal of or interest on said bonds so canceled and refund to the respective persons paying the same the funds, if any, in the custody of the county treasurer collected for the purpose of meeting the principal of and interest on such bonds so canceled.
§ 85-7-2105, MCA