Beginning in 1956 the Southern Pacific Railroad began major upgrades to their premier Sunset Route between Colton, CA and Yuma, AZ. These upgrades would focus on both ends of the 'Yuma Main' in two very different capacities; on the west end Espee set out to double track the railroad over Beaumont Hill and on the east end install CTC (Centralized Traffic Control) between Indio, CA and Yuma, AZ. Well over half a century later the remains of that effort can still be found protecting movements on the Sunset Route, now operated by the Union Pacific Railroad, successor to the Espee. While their numbers have dwindled down over the last decade a precious handful of Union Switch & Signal searchlights, now integrated into today's modern railroad, provide a welcome reminder of the Southern Pacific. Situated 196' below sea level, along the banks of the Salton Sea, the distributed power unit on an eastbound manifest streaks passed the west end of Mortmar siding, location to one of only a few remaining US&S searchlight installations on the Yuma Subdivision.
