Turnouts in Curves

John,
From my experience in track design and construction, railroads try to avoid placing turnouts in curves or within one full length of the longest piece of rolling stock from the start of the nearest curve. In other words, if the longest piece of equipment is 60', they won't allow a switch within 60' of the Point of Curve (PC). Not knowing how these types of engineering issues are handled at the C&TS, I would guess that a plan would have to be carefully drawn out showing current track alignment and the proposed turnout and associated trackage drawn to show where it will be placed and then submitted to them for their review and approval. I believe they have a retired Rio Grande civil engineer who consults for them when required.