Mont. Code Ann. § 3-15-321

Any juror summoned who willfully and without reasonable excuse fails to attend may be attached and compelled to attend. The court may impose a fine not exceeding $50, upon which execution may issue. If the juror was not personally served, the fine must not be imposed until, upon an order to show cause, an opportunity has been offered the juror to be heard. The court may for good cause remit, modify, or cause any fine collected to be refunded.