Re: Early D&RG locomotives?

Yes, that is absolutly true. The D&RG Class 25 of which the Montezuma is one of, measured 6' to the top of the boiler. Other statistics show 4' 8" to the center of the smokebox door, 9' 9" to the top of the stack and an overall length of 35' 4" including the tender.
My source is the book: "Narrow Gauge East From Denver, The Colorado Eastern Railroad" by John C. Newell and P.R. "Bob" Griswold. There is a scale drawing of this class of engine, plus many photos with people standing by the CE #6 which was the former D&RG "Ute" a sister to the "Montezuma". The #6 lasted until 1915 when the Colorado Eastern was mercifilly shut down. It's too bad that someone didn't have the foresight to preserve this engine.
regards,
Don F.