Thank you for this information, it does help me settle with the 1898 date. I wonder why it suddenly resurged in the papers in 1909.
I am glad that you say "supposedly" in reference to running west of Grand Junction. I haven't found any original documentation to back that up. All newspaper references to 107 that I have found so far indicate that it ran
East of Grand Junction, from there to Gunnison. My guess is that since 108 and 109 went to the Utah line, later historians simply assumed that the three 42.5 class were all built specifically for Utah. I haven't found any reference to the 108 or 109 being in Utah until after 1886.