We railfan everyday with a double BNSF track along the ridge near us. We see over 100 coal trains coming out of and back to the Wyoming mine plus many freights. So we have our own model railroad!
That is "Crawford Hill" where they use pushers/helpers to get them up the grade on their trek southeast. After they get to Belmont they unhook the pusher and head back down to hook onto their next full load. Belmont Tunnel, the only train tunnel in the state of Nebraska is near that line.(of course not in service anymore)
But, there isn't an RV park with a view of this track because no one would want to tear up good pasture to build one nor would any RVer want to drive down these dusty county roads to park there.
We get a lot of railfans out here. Belmont isn't really much of a town with about 3 residents, off a dirt road so I'd not advice taking any type of RV rig in there because it might be a bit tough to find a place to turn around, let alone park. The nearest RV park is Fort Robinson so a car trip out to see the trains is the best bet. Horseshoe bend, on the way up Crawford Hill is only visible on Googleearth maps because one can't get close to it without hiking over ridges across private property and railroad right of ways on foot.
Trespassing is wrong! We had some folks stop by about a month ago, park in our pasture without asking, left their car running for AC, the hot exhaust pipe touching dry grass, indeed a fire hazzard. We let them hike in to see the train but asked them to move the car to the county road so the whole country wouldn't catch fire!
The main rule for railfans...just because there is an open gate does not mean people are free to enter. ALWAYS ask permission of private property owners. However the railroad won't allow trespassing. Folks who enter private property don't know what they are getting into anyways...could be a washed out road, bad bull that will take them out or they could get stuck. Most farm & ranch roads are meant for 4x4 trucks and tractors. So do come out to see the trains but please stay on public roads for your own safety and that of our livestock and land!