Union Pacific’s 10 SDP35s were originally ordered to replace aging E-units in passenger service, and they did, briefly. But by March 19, 1966, just six months after delivery, the 2500-hp units could more often be found running fast freight. Here one-half of the fleet, westbound behind 1404, descends on Hermosa. The twin tunnels and the 8,014-foot summit of Sherman Hill, highest point on the UP, lie just beyond the distant signal bridge.
