Prior to UPs massive order of SD70M and SD70M-2s the locomotive fleet to a large extent subsisted upon weary Southern Pacific locomotives. Ex-SP SD40T-2 No. 8243 has been given a UP treatment as it leads a post-merger power consist past the US&S Style B lower quads near Robsart, NM with Kansas City (18th St.) to West Colton symbol MKSWC-02.