Mont. Code Ann. § 17-5-1622

A pledge by the board is valid and binding from the time the pledge is made. The revenues, money, or property pledged and thereafter received by the board is immediately subject to the lien of the pledge without any physical delivery thereof or further act. The lien of any pledge is valid and binding against all parties having claims of any kind in tort, contract, or otherwise against the board, irrespective of whether such parties have notice thereof. Neither the resolution nor any other instrument by which a pledge is created need be recorded.