The 2013 Ram 3500 Laramie Longhorn Crew Cab Heavy Duty Pickup is built to tow. So we decided to try to tow with it up one of the steepest and highest American Highways. From Dillion, Colorado to the Eisenhower Tunnel U.S. I-70 climbs 8 miles to a maximum elevation of 11,158 feet or 3,401 meters. That's enough elevation and grade to test the most powerful of pickups. Is the Ram 3500 Heavy duty up to the task of towing a 17,000 pound horse trailer to the top of the tunnel? Part 3.