Four Montana Rail Link EMD SD70ACes add some mountain-climbing muscle as a manned helper set cut in the middle of a westbound BNSF freight as they cross Skyline Trestle just west of Skyline, Montana, on June 29, 2017. The train is climbing the steep 2.2 percent westward grade out of Helena and is almost to the summit of the Mullan Pass, with the head end near the east portal of Mullan Tunnel.
