It has been recommended that I need to read the January/February 1998 issue (No. 10) of Vintage Rails.
The cover says “Narrow Gauge Steam Bonanza” and they say it really is one.
It was pointed out that there is an article “Narrow Tracks and Slow Time” by Vernon J. Glover that is the best history of the Denver & Rio Grande Western with a dozen pages full of D&RGW historical details.
In the article are things like the engines that ran (yes they used Baldwin Moguls), how long the trains were (12 boxcars or 13 coal cars), how fast they ran (8 - 12 mph) the radius of the curves (30 degrees - 193’ radius) and the percent of grade (4%).
And they say that’s not all. There is also a 2 page article of then current Cumbres & Toltec operations plus more D&RGW & Narrow Gauge articles.
And Vintage Rails still has back copies:
http://www.pentrex.com/vtr010.html
This is probably a must have reading for Narrow Gauge and D&RGW fans in particular.