The Union Pacific Journals show an entry dated, Dec. 1886 for the purchase of 100 30' TC&StL coal cars for the Utah & Northern, where they were numbered in the 9500's.
What is odd is that at that time the U&N was in the process of being converted to standard gauge. And sure enough records indicate that the U&N 9500's began showing up in Colorado on the DSP&P as early as July of 1886.
The Denver Railroad, Land & Coal Co, predecessor of the Colorado Eastern also purchased a number of TC&StL coal cars
Another purchaser was the Ohio River & Western