And the Horseshoe Curve was something to behold! On my first trip in 1987, I was lucky to sit on the "fireman's" side of the coach when I boarded in Lewistown. I made sure to do that on all subsequent trips. Here's a YouTube link to some scenes from a layout modeling the Curve as well as the Altoona environs:
https://www.youtube.com/watch?v=iLT5IuW4T3I
Looks like the only PRR rolling stock they've got running is a 3-car heavyweight Broadway consist, but it conveys the idea. I'd love to run a train on this pike.