The operation of vehicles or combinations of vehicles having dimensions or weights in excess of the maximum limits specified in 61-10-101 through 61-10-104 and 61-10-106 through 61-10-108 is permitted only if authorized by special permit issued under 61-10-121 through 61-10-125 by the department of transportation or its agents or the highway patrol.
Operation Without Special Permits Prohibited
Mont. Code Ann. § 61-10-109, under Standards, Permits, and Fees.
Mont. Code Ann. § 61-10-109