Brian:
I am working on several books on the D&RGW and RGS and have quite a bit of data, but I could not find anything on 216. I have found tons of data on C16s and have passed much of it on to Dennis O'Berry who is working on a C-16 book. I think 216 might have been used out of Leadville on the Blue River and Ibex branches. The Salida, Gunnison, and Alamosa newspapers had lots of railroad news, but the Leadville papers didn't have as much...they had three railroads in town and I guess they didn't think it important. The D&RGW records have tons of operational data such as this item from 1925...
February 23, 1925
278 and 210 with Flanger OL and Caboose 0584
Salida to Sargents flanger turn (278 eastbound with OL and 0584, 210 light eastbound
If I find anything, will pass it on.
Jerry Day