Mont. Code Ann. § 7-4-2521

Any person employed by a county may file with the appointing power a designation of a person who, notwithstanding any other provision of law, is entitled, on the death of the employee, to receive all warrants or paychecks that would have been payable to the decedent. The employee may change the designation from time to time. A designated person shall claim the warrants or paychecks from the county clerk, and on sufficient proof of identity, the county clerk shall reissue the warrant or paycheck in the name of the designated person and deliver the warrant or paycheck to the designated person.