Employees of the department designated or appointed as peace officers under 61-10-154 or 61-12-201 may when officially dressed make reasonable inspections of vehicle registration receipts, department receipts and registrations, special permits, and other documents required to be carried in or for a vehicle traveling on the public highways of Montana.
Power To Inspect Vehicle Registration, Receipts, And Other Documents
Mont. Code Ann. § 61-12-205, under Enforcement by Department of Transportation Personnel.
Mont. Code Ann. § 61-12-205