Terry:
Without seeing it, it would be hard to know if has been published before. It sounds like one of many photographs taken by Jackson, a photographer hired by the D&RG.
The label on the photograph is incorrect. The Black Canon at Curicantii Needle is not Colorado Springs. It is west of Gunnison, Colorado.
If you want to sell it, you might consider taking a digital photo of it and post it on e-Bay or here.