... central California scrublands...
You made me chuckle -
Southern California. Those scenes are capturing locations in and around Cajon Pass. First pic is the original Summit, second seems to be Lugo, and the third is San Bernardino. The fourth
could be intended to paraphrase the bridges at Leon, although the scenery vibe could also represent the track split at Ilmon (between Tehachapi and Bakersfield) before the bridge was washed-out... though I might be misremembering, the Ilmon bridge may have been a through-girder. Anyway, whoever did the scenery work did a credible job of creating the essence of the area.
The ML-4000s are cool. The prototypes were retired a year or two before I was seriously railfanning, but I did see the Alco DH-643 in Bakersfield once (Alco's diesel-hydraulic competitor to the KMs). Breaking your fantasy a little bit here, they were never to my knowledge used in passenger service - no steam generators.
