In a similar discussion a while back, someone suggested Leadville to Canon City, CO. Follow the Arkansas River downhill and downstream, there's only one significant uphill to go around Royal Gorge 10 miles out of Canon City. The terrain is beautiful, and if you need to recover a day before heading home, take the train up the gorge or a whitewater rafting trip. You might want to delay until mid-June for the rafting, though.