The Boone and Scenic Valley Railroad in Boone, Iowa, is a relatively small operation but well worth a visit. If the tourist stuff isn't enough there is UP Yard in the town. The steam locomotive was purchased new from China, the last or one of the last to be built. According to their website the locomotive is currently awaiting a mandatory inspection that cost $125K for which they are seeking donations.
Note: This is the last, I think, of my sample pics of steam excursion railroads. The organizations' websites can provide more, and more up to date, info than I can but feel free to send me a PM or email with questions.
: