A heavy 100-car Union Pacific Herzog ballast train plods westbound up the two-percent grade of the Moffat Tunnel Subdivision. The train is climbing through four tunnels at South Draw just east of Crescent, Colorado, on May 17, 2022. Three motors up front are curving toward Tunnel 17 on the right, after spewing a large amount of exhaust working through Tunnel 16. Three more six-axle UP locomotives are cut in mid-train and are hidden inside Tunnel 15 in the center of the scene. A Kansas City Southern GE and another UP motor work hard as a rear DPU on the left, catching some fresh air between Tunnel Nos. 12 and 13.