Mysterious Narrow Gauge diesel in Central City

When I was a teenager in 1990 my family took a trip to Colorado with one of our planned stops being Central City.  I wanted desperately to ride the Blackhawk and Central City Narrow Gauge Railroad and see C&S 71 in steam.  Unfortunately, the railroad had called it quits unbeknownst to us and we found all the equipment sitting idle at the boarding area.

One curious piece of rolling stock was this little track engine.

Is anyone aware of what this was or if it still survives?