Welcome to the Aspen Backcountry Marathon and Half Marathon, where trail runners get to experience, well, the backcountry of Aspen; amongst the most beautiful natural landscapes in the United States. Scenic Views, Challenging Course, Trail Runners. Known as one of the most scenic yet challenging trail running marathon and half marathon courses in Colorado, the Aspen Backcountry Marathon and Half Marathon offers views of Elk Mountain and more throughout the many ascents and descents of the race terrain. Surrounding beautiful Aspen, a destination in and of itself, this course is a destination rae for many, especially the msot experienced of trail runners, and for more reason than one.