I saw on the safety video that only steamers that are propain fired are allowed. Is this true?

Yes only propane fired steam engines can be used at Train Mountain due to fire hazzard!!

I'm guessing only.. it's also a reliability issue to use propane to control an engine. Oil and especially shoveling coal is not as easy to deal with....another reason for their demise in real trains.

I dont know, i like train history but not a history buff. My thoughts are that way back when they didnt have propane and now days because of bogus carbon print restrictions propane is the only fuel allowed just my thoughts though nothing to back it up with.