The Colorado Trail Foundation is the nonprofit and volunteers who build and maintain the 486-mile trail over the Rocky Mountains between Denver and Durango. ColoradoTrail.org • The Colorado Trail Foundation builds and maintains The Colorado Trail, all 567 miles between Denver and Durango, thanks to support from our Volunteers and Donors. Please join us and support this effort. • 501(c)(3) Non-profit The CTF builds and maintains the 567-mile hike-, bike- and horse-friendly Colorado Trail with the help of 600 volunteers and 3,000 donors each year. This trail provides multi-day, inspirational, and educational values keyed to the diverse, high mountain, natural environment.