Western Railroad Discussion > EMD GP59 Demonstrator locos question

Trying to track down if any of the EMD GP59 demo locomotives(#s 8-10) have run over any Rio Grande territory in CO or UT? 
So far I have only found 2 images of EMD #10 sitting on a siding on Tennessee Pass. 
To narrow it down, the timeframe would be approx. 1985 to 1987 ish.  I've sifted through all images, threads here I could find and just those 2 photos found thus far.
Any info., article reference or photos would be greatly appreciated!

Rochester, NY
Chuck