I call BS on this. I live in Colorado too and rode today from downtown Denver to the top of Mt. Evans. That's 8,900 feet of gain to an elevation of 14,100 feet, and I am pretty much dead right now. Unless you're doing laps on Mt. Evans or Grand Mesa or back-and-forths on the Peak to Peak Highway from Idaho Springs to Estes Park, I don't see how you can get 10,000 feet in a day ride from Boulder. Please enlighten us.