well, since you're already in Colorado, you can almost never leave the state or the bordering states, you're in playground central!
Maroon Bells 4 Pass Loop, outside of Aspen, always makes backpacker's top 10 list.
Utah has amazing NP's and wilderness playgrounds, including Grand Staircase Escalante.
Rocky Mtn NP is fantastic, reserve your campsites early.
Since you seem to be near or familiar with the Ouray area, the Weminuche wilderness is MASSIVE and beautiful.
Just south you have the great NF's and wilderness areas in NM.
And Ouray is only 6hrs from the grand canyon!
I'm so jealous...