N.D. Cent. Code § 61-02-47: When bonds to mature - Callable before maturity

The bonds which may be issued by the commission shall mature at such time or times, either serially or at one time, in not more than forty years from their date, or dates, as may be fixed by the resolution of the commission, but may be made callable before maturity, if so stated in the resolution and on the face of each bond.