I made these views with my FujiFilm X-T1 digital camera of the former Chicago & North Western Chicago-Madison-Twin Cities mainline at Evansville, Wisconsin.
John Gruber was giving me a tour of the line. He explained that in its heyday this route had been a double track mainline with a top speed of 75 mph.
Today it is a truncated vestige of that earlier era. The tracks are now operated by Union Pacific to serve local freight customers. No fast Pacifics with varnish in tow any more.
To ensure new material daily, Tracking the Light is coasting on autopilot while Brian is traveling.
Good guess! My Tucumcari Line photo were on K25.
It reminds me of your photo at Dusk of another famous line, the Tucumcari of SP
Let me see, was that using Kodachrome?