That illustrates the point. They use a diesel on the Frontier Days runs because the train is usually 20-23 cars, whcih would have been run in 2 sections back in "real" steam days, due to the long climb to Speer, some of which is 1.24% and which was a helper grade in steam days. On the return trip from Cheyenne, the diesel provides dynamic braking down that hill, which, unless you just really like the smell of hot composition disc brake shoes, is a real treat.

The other reason is that schedule on this particular train in very important to the people who are paying for this train. Far more important than what lineside foamers may think about it.