I thought I had a bunch of these, but this is the only other one I found in a quick search of my collection:
Like the Idaho Springs photo above, it's clearly a later print since it shows a zip code for the company, which dates it to 1963 or later, while the photo is from the 1920s.
I do have a stereo view from the Rocky Mountain View Company, which is hand dated on the back 1887. I'm pretty sure this was a completely different company.
There must have been some connection between Glenn Gebhardt (apparently the owner of the Rocky Mountain View Company) and Frank Duca, who also published a lot of real photo postcards. This card appears to be the next in sequence to the Idaho Springs photo above, but it's from Duca:
And this one has Gebhardt's ID on the negative, but was published by Duca: