Montana Title 61. Motor Vehicles § 61-9-436. Certain vehicles to carry tire traction devices during winter months

(1)(a) Except as provided in subsection (1)(b), from October 1 through April 30, a person operating a motor truck of 26,001 GVW or greater towing a trailer on a mountain pass or on a similar stretch of highway designated by the department of transportation as a place where traction control devices are potentially required shall carry in the vehicle approved traction control devices prescribed by the department.

(b) The requirement of subsection (1)(a) does not apply to a vehicle with four-wheel drive.