I have ridden two tours in bike tours in CO. Bicycle Tour of Colorado (http://www.bicycletourcolorado.com/index.php) is the older larger tour. Colorado Rocky Mountain Bicycle Tour (http://www.crmbt.com/home.html)is the newer, smaller tour. Since CRMBT is offering a ride up Mt Evans in 2013, I would go for this tour. Mt Evans offers you a ride up the highest paved road in NA that a cyclist is allowed to ride. Recently, Pikes Peak has been fully paved but is not open except on special occasions to cyclists (it is also incredibly difficult; a 12% grade at 13,000 feet is very different than 12% in Maryland). Mt Evans never has a grade above 8% and averages about 4.5%
The weather in the Rocky Mountains is unbelievably changeable. Be prepared for 40 degree+ temperature shifts on the same day. Be prepared for rain on mountain tops after 12 noon. But be prepared for a really great time and some of the most beautiful vistas you will ever see on an a bike tour.
Ed Cahill

I've done Ride the Rockies in the past and it was epic and incredible; highly recommend it. I don't think it works with your timeframe (it starts June 9), but maybe another year... It's popular so they use a lottery system to do registrations. When I rode it they had sag wagons, rest stops with great food, and a keg truck following the tour.

I like the keg truck idea!

( especially at altitude)...

I've already signed up for the one Ed Cahill mentioned- works with my time frame & I've had some good correspondence with the leaders online!