GVDOBLER's suggestion of Apex (also Sloan and Erie) is a good one. That's desert, of course. Off the beaten path? East of Las Vegas is where the best photo locations through desert mountains are, but, they start at least an hour east. Garnet is a good location, especially with a telephoto lens. Don't know which way you are passing through, but a detour using the old highway (US 93) through Caliente will get you to some of them. Others require the ability to drive on somewhat primitive desert roads. There was a liquor distributor's sales representative who lived in Las Vegas and took a lot of photos east of town.
If you leave the city in either direction to take train photos, be sure to have drinking water with you, and, if nosing around east of town, out of cell phone range, tell someone where you are headed and then tell them again when you get back to cell phone territory. It's not terribly dangerous normally; just stay hydrated and take sensible precautions so they can search for you in case of car trouble. If you see a rainstorm, even a distant one, stay on pavement. You could be marooned by flash floods if you're on the primitive roads. (Thus the phone call to someone who knows where you are likely to be.)