What was the first tourist RR in Colorado?

What was the first tourist railroad in Colorado to utilize a former common carrier line? 

It would seem to be Cripple Creek and Victor’s 2-foot gauge route constructed on the old Midland Terminal/Florence and Cripple Creek right-of-way in 1967. 

A chance view of someone’s home movie footage posted to Youtube, however, revealed a tourist line that preceded the Cripple Creek and Victor by at least 14 years. The origin of this line, and its disappearance, is a mystery to me and I hope that this post elicits more information from those who might know.

A gentleman posted footage of a 1953 family vacation to Colorado which included a visit to Idaho Springs. In the video, a 15-inch gauge live-steam train hauling kids first crosses a bridge (constructed by this railroad? That would seem to be an expensive item) over Clear Creek and then turns westward past the Argo Mine loading chutes. 

These chutes were used in the past to load Colorado & Southern narrow gauge gondolas. 

At least 12 years after the C&S rails had been salvaged in 1941, this unknown live-steam group had laid 15-inch gauge track on the abandoned right-of-way. The video follows the train as it passes the Argo Mill. From there, it is hard to determine where the track ends.

Could this be the first time track for an active railroad had been relaid on an abandoned railroad grade in Colorado?

I don’t have any information on who started this line, when the tracks were laid, or when they were removed. 

The only follow-up is that the narrator of the home movie shows what became of the engine. It later went to the Comanche Crossing & Eastern live-steam railroad where it is today. Sometime after the 1953 video, the engine’s cab was rebuilt and now includes a CC&E logo patterned after the C&S’ Columbine logo.

While this is not the first full-scale tourist railroad in Colorado (Cripple Creek and Victor probably gets that honor), it is likely the first active tourist track relaid on a narrow gauge roadbed.

Here is the video itself. At 2:13 the family takes a bus trip to Idaho Springs and rides the live-steam train past the Argo Mill chutes.

After that segment, the narrator relates how descendants of his would later learn to drive the same locomotive, now lettered with a C&S style logo for the Comanche Crossing & Eastern.  Does anyone know where this locomotive is today?

The C&S shows up again when there is a quick shot of C&S 60 at 3:24 in gleaming paint, though lettered for the Burlington Route.  It is still at the original location with the log gift shop behind.