Well, give Google a few days and you can cite this very article -- in an oddly self-referential way -- pointing that Colorado has more entrepreneurs per capita than any other state in the union! :-)

More seriously, this is an interesting research question, so let's start by popping over to my favorite search engine (Google: is there any other?) and see what we can dig up.

My first search suggests that we might have a bit of confusion. Search for "most entrepreneurial state" and you'll find that it's either Utah, Alaska, California, Vermont or, perhaps, Texas. None of those, alas, are Colorado.

On the other hand, according to MicroBusiness Development Colorado is the second most entrepreneurial state in the U.S.. Is that good enough? :-)

Digging further, searching ".gov" sites, reveals research by the Small Business Administration that rates Glenwood Springs, Colorado as the most entrepreneurial city in the United States:

"Using the REI [Regional Entrepreneurship Index] measure of entrepreneurship capacity and performance, Glenwood Springs, Colorado ranks as the nationís most entrepreneurial region."

Here are some additional references on that subject: a press release from the SBA, The State Science & Technology Institute, and my own article on the subject from my business blog.

The final word: as with much research that's subjective (how do you measure entrepreneurship?) it's no surprise to see conflicting and ambiguous results. Maybe that's part of the story here, though?