Amtrak #326 is, indeed, an E8A, originally UP 929A according to one Amtrak roster that I have and was too lazy took at last night. At one time I had another roster which showed several of the E units as E8/9 supposedly indicating some kind of up grade. Maybe they cleaned the windows?

The shot is taken at the East end of the now gone wooden shed that was to the West of the "Big Hole", Tunnel #41 and just below the now removed #1 track.

As for exposure, that was shot with Kodachrome 25 (the best color film ever made)and my settings were determined by the meter. At that time I was using a Honeywell Pentax Spotmatic which had thru the lens metering but required manual setting of the aperature and shutter speed.
By that time, I had come to rely on my own judgement far more than the meter. My bright sun setting was F4 at a 500th and I used that same setting in the snow and got proper exposure of the Amtrak units.

Several years before, I had learned my lesson with an automatic 8mm movie camera. In most circumstance, with or without snow, the camera would stop down the apreature as the train got closer and brighter. I took a light setting and then locked the meter so the engine or whatever would not close it down and underexpose. The old electric eyes read the whole frame and could really screw up a scene with a shiny train.