The Colorado Trail offers amazing singletrack, incredible views, some steep high-altitude climbs, and it passes through 6 wilderness areas. It is probably Colorado's best long-distance backpacking trail.
Multiple trailheads around the state, click one of the individual segment listings above to get directions to a particular staring point. From Denver, start off S. Platte Canyon Rd.
http://www.tripleblaze.com/trail.php?c=3&i=2122