With the passage of years, I'm a little rusty about NM/CO SHPO requirements and policy interpretation, but my reading of NPS standards may not leave a lot of room for a non-historic turntable & roundhouse at the north end yard location, Especially if it alters or changes the view/perspective of the extant 2 stall structure.
If you read
all the standards as a whole, and not just the reconstruction standards, a new roundhouse amid the major icons of the Chama yard becomes more problematic from a historical perspective. For example, see [
www.nps.gov] and note #2 of the Standards for Preservation:
"
The historic character of a property will be retained and preserved. The replacement of intact or repairable historic materials or alteration of features, spaces, and spatial relationships that characterize a property will be avoided."
Constructing a roundhouse/turntable in this location might add visitor interest, especially to enthusiasts, and add value operationally. But it could be veiwed far differently by the SHPO agencies. There are valid arguments on both sides.