You are in the CarrTracks website Picture Gallery.
Alco switcher 2323 works the west end of Barstow Yard. This S2 switcher was built in July 1942 and was retired in 1973. In the background is the US91 bridge over the railroad yard.
That is West Tower and the junction with the line from Mojave. Barstow is milepost zero for most of the Santa Fe trackage in southern California.