We will do the ride again, and when we do, we will go from Hill City to Keystone (what we did the first time) and purchase the earliest departure we can on the steam train (which was 10:00, I believe) and plan for at least 4 hours, more if they have later return trips. We planned in a two hour stay in Keystone, but could have easily stayed for several more hours. We didn't stop at the museum, because we were staying in Hill City and thought we would have the chance to go back, but didn't had the time. We should have arrived in time to tour it before our departure. You could probably spend a few hours in Hill City between the museum and the shops downtown, but there is dedinitely more in Keystone.
I would wait for the next train to get back and spend a couple hours in Hill City. We did the ride back to back and didn't have enough time to look in the gift shop, and we got a little tired sitting for 2 hours straight. Hill City would be well worth spending a couple hours touring around.
I liked the trip from Hill City to Keystone better then the other way around. Both trips are just as beautiful. You can hear the history better from Hill City to Keystone. I do not know if you can by a ticket early and take a later train. If you can do that then yes you would have time for the museum and all that. If not there is only a 15 minute stop for them to move the engine and water up. I hope that helps you. Was just there last week.
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