The Bluefield Train Yard runs parallel to Rt. 52 for a section. If you have found your way to historic Bluefield via Rt. 460 and then Rt. 52 you must only stay on 52 west for a few hundred more yards.
The Bluefield Train yard is a nice sight to see, but not one will constitute a long stop on your trip. Since the rail yard is still active you must view it from the road and or while passing by