NOT railfan or tourist service. I.E. regular commercial revenue earning service. What I want to know is what year it was and if possible what railroad and where. Of couse it is quite likely that the last one of all was in industrial use at a factory or similar - it would be nice to know where and when this was too.
I appreciate this is rather a grey area. In Britain, technically, the Vale of Rheidol Railway, Snowdon Mountain Railway and Isle of Man Railway have just carried on running and never dieselised - (fully at least) but these lines are run for tourists and steam is part of the 'attraction'. So I think that rules out the Pikes Peak railroad as one example.
Thank you in advance.