No, it was the Big Boy, I was just trying to guesstimate a date based on when I retired. As a matter of fact supposition, its stop in Denver might have been on its way to CA. At my age it's hard to specifically tag years with certainty.
For further interest (ha!) and amusement (ha!):
The spur was right by my building, off of the rail yard which is no longer there either. Union Station is still there, but no trains, just buses. If you do an aerial view of 15th and Wewatta in Denver, my building was the dark building north of the one which has the Fogo de Chao restaurant flagged in its south corner and the curved building nearby is the Gates (Rubber Company) building. The loco was parked directly between Gates and my building. That whole area has changed enormously since they closed the rail yard. The triangular building wasn't there at the time; it was just a grassy area. Heaven forbid my having to visit that area in Denver again --or Denver at all --but if I did, I'd probably be totally confozzled.