I'm not sure if you're still looking for advice here... but I wanted to answer anyway. I'm not all that familiar with Fort Collins itself, I live about an hour away, but if you're not above a bit of a drive go to Estes Park, Colorado. There are at least three shops up there that I frequent every time I pass through. One was named 'The Ore Cart', the other was simply 'The Rock Shop', and I forget the name of the third.. but it's hard to miss. It's right on main street and has huge castings of a triceratops skull and T-rex skull in the front windows. My personal favorite is The Ore Cart. :)