Fifth Wheels Fifth Wheels. Montana builds RVs that inspire. To do this Montana designs fifth wheels to provide enduring pleasure over the long haul and in every aspect of the ownership experience. 2011 Montana 3665RE 3665 RE Montana North America's #1 Selling Fifth Wheel for Nine Consecutive Years. Montana fifth wheels enable you to achieve all three. the right inspiration leads you to achieve greatness whether you are vacationing adventuring or just relaxing...