Personally, I have only spent a total of about four hours in Alaska in my lifetime, and that was during a stopover on a flight to Korea. Still, I plan to spend an extended amount of time there at some point in the not-too-distant future, God willing, and I just enjoy studying the history and operations of that interesting railroad (also has Army ties, of course).
For information about the railroad and the terrain it operates in, you might try just doing a Google search for Alaska Railroad and then click on "images" in the menu bar. Many, many photos there.
Also, Pentrex and perhaps others have produced Alaska RR videos in years past. I have probably four or five of them and they provide a wealth of info about the railroad and how and where it operates.
My own layout will not be an accurate representation of any particular area along the Alaska RR, but will just represent things the way I visualize they might be.