In July 1967, Erick Nelson and I were in Durango for a few days.
To our profound amazement, one morning the hostlers brought out #487 and then #498 over to the ashpit, where the fires were dropped, after the engines were coaled and sanded.
Those two big hogs had brought in a freight a couple of days previously, and we were absolutely convinced we would never again see a 480 or a 490 class engine under steam.
As it is, that was the only occasion we ever saw any of the big engines under steam on the D&RGW.
So the phrase "never say never" is valid, but the window gets a lot smaller the more time goes by.
I'll guarantee you one thing, we all would have been stunned to know how much stuff is running (and has recently run) now 39 years later. There are certainly different thoughts being thunk now. Back then, every trip could have been another "last run".