with the IMBA in Boulder I would call it a cycling haven. However, now MTB allowed in the Boulder Open spaces makes it odd.

Colorado Springs houses a velodrome and many pro/olympic cyclists (Danny Pate and Mike Creed, to name a few).

Durango doesn't hurt either.

How about the fact that we're close to Moab, but we don't have an overwhelming Mormon culture (not that it's a bad thing ).