The course is based on the mail routes of the 1880s, connecting the two towns. In this extreme endurance event, racers will climb more than 7,800 vertical feet and navigate in a self-supported backcountry race that tests them physically and mentally. To maintain safety in the backcountry, racers compete in teams of two and are required to carry mandatory gear.

Held annually since 1998, it has earned a reputation as a true test of toughness for elite local, national and international athletes.