4-8-4 entering Moffat Tunnel By Angela Cotey | May 2, 2023 Email Newsletter Get the newest photos, videos, stories, and more from Trains.com brands. Sign-up for email today! Get Updates Rio Grande engine 1703, from the road’s first group of 4-8-4s, heads a westbound train out of Denver into the 6.2-mile darkness of Moffat Tunnel in August 1950. W. R. Berg Jr. photo