Mont. Code Ann. § 81-1-304

With the approval of either the federal veterinarian in charge in this state or the United States department of agriculture, the department of livestock may appoint federal veterinarians or federal lay inspectors stationed in this state, as deputies or agents for the department. All federal officers so appointed as deputies or agents of the department possess the powers and duties of regular deputies or agents of the department, but they shall act without compensation and hold office only at the pleasure of the department.