Western class 1's aren't as friendly as Jim Speaker's experience would indicate. The operative term is "stay off of railroad property". Take pictures from public property, using a telephoto shot when necessary.

At times some of us gather in the evening at a local NAPA store's parking lot adjacent to the BNSF mainline to watch trains. Occasionally local cops have stopped to see what we were doing. They are generally friendly after having been informed about the "train watching" hobby. If they still don't get it, then I trot out the "bird watching" analogy. Strangely, everybody seems to understand bird watchers. I explain that trains are like birds; every one is slightly different; locos, consists, where from, where going, etc. Then they get it.

One night several years ago three of us were in a car on a public street driving adjacent to a slow moving UP train. Suddenly the scanner picked up this train, reporting to their Dispatcher, a "suspicious car following them" --- that would be US! I slowed to drop back, made a U-turn, and we immediately exited the area! If, by chance, cops were called and responded, we were long gone by the time they got there.

Shortlines are generally a lot more receptive to railfans as long as they act safely and don't do stupid things. Some will even offer cab rides to people who are polite and act reasonably.