I had always assumed that 4014 was intended on being in steam for the 150th anniversary of Promontory.
I finally got to the place in 2012, during the cross-country sightseeing trip my wife and I took. It's small, but very nice. Well worth the detour to get there. Nearby Ogden also has a good RR museum, but I didn't have time to do that and Promontory. Both steam locomotives were in steam that day and we even had to stop at a grade crossing for 119 to go by as we drove up to the place!