Mont. Code Ann. § 85-7-1952

In any contract entered into between an irrigation district and the United States hereunder, the board of commissioners shall have the power to levy assessments for the United States contract fund against all of the land within the district for any and all of the purposes enumerated in the laws of Montana and, in addition thereto, the power to levy assessments in compliance with such contract, including such deficiency assessments as will enable the district to meet established or estimated delinquencies in making payments to the United States because of the failure of landowners to pay the assessments levied against their lands in the district.