Alaska · Big Lake

Susitna

Run every year since 1997, the Susitna 100 is the oldest consecutively-held winter endurance race in North America. The 100-mile out-and-back starts and ends at Happy Trails Kennels in Big Lake, crossing frozen lakes, rivers, and bogs on packed snowmachine trails through the Susitna Valley; checkpoints average 16 miles apart. Runners, skiers, and fat bikers compete simultaneously. Mandatory gear — a -20°F sleeping bag, bivy or tent, and 3,000 calories — adds 15–20 pounds. The 48-hour cutoff governs all divisions.