Black Canon, Curicantii Needle

Hello! We recently became the owners of an extremely large original print dating from the late 19th Century. It's entitled Black Canon at Curicantii Needle, Colorado Springs, CO, and is attributed to George Mellen (the famous 19th Century CO railroad documentary photographer). As far as we can tell the photo is on it's original mount in the original frame. There is a tiny bit of damage to the print in the upper left quadrant. It is an AMAZINGLY evocotive picture -- there's an angler standing in the foreground on the shore of a raging river and a stunning view of the rail system as it winds its way along the edge of the valley floor.
We've been trying to learn more about narrow gauge railroads just so we can have a better understand of the image's importance. Can anyone tell me anything about it? Has anyone ever seen another copy of this print?
Frankly, we would be be happy to sell the picture to someone who could better appreciate its significance. If anyone on this message board is interested -- or knows something about the picture and wants to help two railroad novices learn more about it -- we'd really appreciate hearing from you.
Our email address is <tfing3705@yahoo.com>. Meanwhile, we'll just say: thanks a bunch!
Yours,
Terry and Keith Manies