He, he, that's pretty cool
Back to my original point. I've seen plenty of photos of trains passing over ridges etc. Are they exaggerated by telephoto lenses perhaps?
Also, by crossing point, I mean crossovers where trains with between tracks, not grade crossings.
The Midwest is not flat as a pancake as they say and has rolling hills. Areas such as northern Nebraska, up on the South Dakota border, for example, is in what is called the Sand Hills. These are huge rolling hills where the railroads snake in between below in the valleys or go across the top of them.
My recommendation is to take a look at Google Earth and pick an area such as North Platte Nebraska, Valentine, Nebraska, Mobridge, South Dakota, Bizmark, North Dakota, Rapid City, South Dakota, and take view from the various highways and back roads and you'll see what I mean.
There are going to be some areas that do flatten out as you head into southwestern Texas down past the panhandle on the New Mexico border, although, there are some steep hills and mountains there too, and there are some very flat areas like that in eastern Colorado on the Oklahoma and Kansas borders, but for the most part, areas roll along with some steeper than others.
Yes cities are quite spread apart and so are towns. The landscape is covered with what is called prairie grasslands and very large farms for wheat, corn, and cattle as well as soybeans. You'll find the railroads have lots of elevators located along various sidings along the way. In some places, the once longer mainlines are now spurs serving a grain elevator or ethanol plant.