They also saw widespread use around montrose to ridgeway. Most of them were converted from scrapped tenders and received numbers as they were scrapped.
They are interesting to compare to the C&S dual gauge cars, (034 being one of them) that were narrow gauge flangers with the blades removed and extra couplers added for switching on the dual-gauge mineral belt track around Leadville.
Search for "idler" on photoswest.org and you can get
several pictures of them.
-Nick