The Wagon Loop Trail climbs 1.3 miles from the Browns Creek Trailhead to the intersection with the Colorado Trail. It's a steep, relatively rocky climb, but it's smooth enough that it looks manageable... if you have the lungs and legs to go anaerobic for over a mile at over 9,000 feet.
Browns creek Trailhead
http://www.singletracks.com/item.php?c=1&i=7676