Mee & Knowles are two spectacular and remote canyons in the Black Ridge Canyons Wilderness of the McInnis Canyons National Conservation Area in western Colorado. If you like rugged desert landscape and don't want to see other people, this route is for you! Closing the loop requires around 38 miles of on- and off-trail hiking/running with somewhat tricky navigation. The route is described in Michael Kelsey's Canyon Hiking Guide to the Colorado Plateau.

The Maroon Bells Four Passes Loop is a 28-mile route in the Elk Mountains near Aspen, Colorado. It circumnavigates the Maroon Bells, through some of the most spectacular scenery in the state. I think it just might be the best run in the entire state! It is a challenging route, with 7,500 feet of climbing and descending, numerous creek crossings, and altitudes up to 12,460 feet.