Mac Poor article highlights: Shays on the South Park?

In doing some research for a new Bogies and the Loop article I came across an article by M.C. Poor published in the October 1948 Railway and Locomotive Historical Society Bulletin.  It was entitled "The Locomotives of the South Park R. R."

The following was an interesting excerpt:

"William Cairns and Jesse Frazier both write that the Colo. & Sou. was experimenting with number 25, a Shay engine, on Boreas Pass with a view of perhaps buying it.  Evidently the Shay's performance did not justify its purchase as this engine was sold to a road in Utah."