The area surrounding the depot is full of engines and train cars.
When we arrived the steam engine was nearby and fired up giving off smoke and steam. What an exciting sight. I took our granddaughter to stand in front of it for a picture.
The depot is authentic and fun to just browse around in. There is a nice gift shop and a sandwich bar.
We took the 12:05 Missionary Ridge Local that lasted 55-60 minutes. We called ahead and they said we could buy sandwiches there and take them on the train.
However the 60 minute trip is really in 3 segments: an outbound trip for about 15 minutes, a turntable demonstration and shop tour for about 15 minutes and an inbound trip for another 15 minutes.
We didn't have time to eat before we arrived at the end station and were told to get off the train. In actuality you don't have to get off unless you want to see the turntable demonstration and the shop tour.
I would encourage taking the turntable demonstration and the shop tour and eat elsewhere.
Their web site is here and the TripAdvisor reviews are here.