Mont. Code Ann. § 26-2-107

Each warrant of commitment issued by a court or officer pursuant to this part must specify, particularly, the cause of the commitment. If the warrant is issued for refusing to answer a question, the question must be stated in the warrant. Each warrant to arrest or commit a witness pursuant to this part must be directed to the sheriff of the county where the witness may be and must be executed by the sheriff in the same manner as process by the district court.