85-7-2133. Role of county officers in collection of tax or assessment. (1) A certified copy of the resolution authorizing the issuance of bonds under this chapter must be filed with the clerk of the board of county commissioners of each county in which the lands of the irrigation district lie, and the special tax or assessment provided for in the resolution must be levied and collected as prescribed and when collected must, by the county treasurer having custody of the funds of the district, be placed in a special fund and used solely for the payment of all bonds issued under the provisions of this chapter and interest on the bonds as long as any of the bonds or interest coupons remain outstanding and unpaid. Whenever the payments are made for amounts due or to become due to the United States under a contract between the district and the United States for which bonds of the district have not been deposited with the United States as provided in 85-7-1906, the special fund must be known as the United States contract fund.

(2) The county treasurer of the county where the office of an irrigation district is located is the custodian of all funds belonging to the district, and the treasurer shall pay out the funds upon the order of the board of commissioners, except payments on bonds and interest for which an order is not necessary. If any portion of the funds belonging to a district has been collected for the purpose of establishing a reserve fund, the county treasurer shall pay that portion to the district on order of the district's board of commissioners who may invest the funds in legal investments backed, insured, or guaranteed by the United States or the state of Montana, including federal and state agency obligations. If money of a district in the United States contract fund established pursuant to subsection (1) is in excess of the amount needed to pay a district's next annual contract obligation or obligations to the United States, the excess or any part of the excess may, upon order of the district's board of commissioners and with the consent of the United States officer administering the contract for which the contract fund has been established, be paid to the district for use in meeting other obligations of the district. The orders of the board of commissioners must be signed by the president and secretary of the board and must bear the official seal of the district.