Mont. Code Ann. § 15-2-305

A district court may make an interlocutory adjudication of an issue pending before the Montana tax appeal board if that issue involves procedure, the admissibility of evidence, or a substantive question of law and does not require the determination of a question of fact. If the petition is granted, the district court shall rule on all issues presented in the petition and the response, regardless of whether a ruling on less than all of the issues is dispositive of the case. Appeals from the ruling of the court may be appealed as in other civil actions.