John:
I have info on the Rogers Tank. I am writing a book on the Crested Butte branch and I am reluctant to post what I have here as it seems to end up in someone's book without a credit line.
I will try to answer your questions without giving away the farm. Rogers was located at MP 322.13 (about six miles from Crested Butte). There was an 8 car siding there. The siding was there first. The tank was built primarily to water rotary plows as the Floresta branch had some of the deepest snow on the D&RGW narrow gauge. They sometimes did not get the line open until the middle of May and once into June. I have more info, but wait for the book.