Mont. Code Ann. § 80-12-308

A pledge made by the authority is valid and binding from the time the pledge is made. The revenues or property pledged and thereafter received by the authority is immediately subject to the lien of the pledge without any physical delivery thereof or further act, and the lien of any pledge is valid and binding against all parties having claims of any kind in tort, contract, or otherwise against the authority, irrespective of whether such parties have notice thereof. The resolution, trust indenture, or any other instrument by which a pledge is created need not be recorded.