The High Lonesome 100 is a challenging ultra marathon trail race held in the Sawatch Range of the Colorado Rocky Mountains. With a 100-mile course featuring 23,500 feet of vertical gain and reaching an elevation of 13,150 feet, it offers a true mountain race experience. The course runs through beautiful singletrack trails, including portions of the National Continental Divide and Colorado Trails, passing through ghost towns, alpine passes, remote basins, and soaring ridges. The event is organized by a dedicated team of volunteers and offers a supportive community for participants.

The website provides information for runners interested in participating in the race, including registration details and requirements. It also offers resources such as the Runner's Guide and Runner's Bill of Rights. For those curious about the course, there are overviews, elevation profiles, maps, aid station information, driving directions for crews, and a detailed course description. Volunteers are also welcomed to contribute to the event's success by signing up for various roles like course marking and aid station support. The High Lonesome 100 is fully permitted through the United States Forest Service, Chaffee County, and the Colorado Land Board.