I am a big fan of both real railroads and model railroads. In the latter category I run a small layout in my basement of the old tinplate Marx trains that I had as a youth. The heirs to the Gary estate love the model trains as well, so I hope it sticks with them as they get older.
Anyway, as for real trains, in southern California is the Tehachapi Loop, where east bound Union Pacific Railroad trains gain elevation through the Tehachapi Pass. It's quite an engineering marvel, made particularly interesting in the fact that from a particular vantage point a single long train can be seen to double back upon itself such that three pieces of it are in view simultaneously. Three!
Hard to explain, so here's a YouTube video. You should take a few minutes to watch from the beginning, but if you are impatient, skip ahead to around 3:35 and watch the lead engine come in from the left side:
If the embedded video playeth not, here's the link.
There connection to Ultrarunning? Many of our favorite running places are rails-to-trails. And some of my most interesting running has been along active rail lines, a practice which I must severely discourage.