Mont. Code Ann. § 17-5-1528

Any pledge made by the board is valid and binding from the time the pledge is made. Revenue, money, or property pledged and received by the board is immediately subject to the lien of the pledge without any physical delivery or further act. The lien of any pledge is valid and binding against all parties having claims of any kind, whether 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 is required to be recorded.