I've been planning a two week vacation to Colorado (10 days really after driving) with a majority of the time in Aspen and Durango before a short stop over in Colorado Springs (basically to go to Pikes Peak and Garden of the Gods). Besides some of the 'guidebook' touristy places, does anyone have any suggestions for possible things to checkout?

The only 'must do' things on this trip from my perspective are the National Parks (Black Canyon, Mesa Verde, and Sand Dunes) and the Durango-Silverton Narrow Gauge Railroad. I have a ton of ideas in my head but thought I'd ask others since it's been 10 years since I lived out that way.