N.D. Cent. Code § 40-54-10
All gravel assessment warrants shall be payable as specified and in such amounts as in the judgment of the governing body will be provided by such special assessments. The warrants shall bear interest at a rate or rates and be sold at a price resulting in average net interest cost not exceeding twelve percent per annum if sold privately. There is no interest rate ceiling on warrants sold at public sale or to the state of North Dakota or any of its agencies or instrumentalities. The warrants may have coupons attached representing each interest payment. The warrants shall state on their face the purpose for which they were issued, and from what fund they are payable, and shall be signed by the executive officer and countersigned by the city auditor under the seal of the municipality. The warrants shall be used in making payment on the contract for the furnishing of gravel, or may be sold for cash at not less than ninety-eight percent of the par value thereof, and proceeds credited to the special fund and used to pay for the gravel project.
N.D.C.C. § 40-54-10