A winter endurance challenge through Alaska’s frozen backcountry
Overview
The Susitna 100 is a rugged winter ultramarathon set in the Susitna River Valley north of Anchorage, Alaska. Participants may complete the 100-mile course by foot, bike, or ski. With no outside support beyond checkpoints, racers must carry mandatory survival gear and navigate snowmachine and dogsled trails under often extreme and unpredictable conditions. This is a true test of endurance, resilience, and self-reliance.
Entry Requirements
Must pass gear check; winter endurance experience strongly recommended
Course
100-mile loop on packed snowmachine and dog sled trails
Terrain includes frozen rivers, lakes, forests, and swamps
Fully self-supported except for staffed checkpoints
Conditions vary from -40°F to 40°F with possible deep snow, overflow, and wind exposure
Logistics
Swag & Medals
Race entry and gear inspection
Wilderness checkpoint support
Post-race celebration
Opportunity to test your limits in a one-of-a-kind winter race
Military scholarship available for active-duty Alaska-based service members
Getting There
Fly into Anchorage International Airport
Pre-race meeting in Anchorage Thursday before race
Most racers stay in Anchorage or Wasilla
Wasilla is ~1 hour drive from Anchorage
Ample parking available at start/finish
Driving Directions
Requirements
Unknown
Policies
Race Policies
No pacers allowed
No course markings; racers must navigate using maps and GPS
No refunds unless race is canceled
Mandatory gear must be carried at all times
Sleds allowed for foot/ski participants; backpack or sled options permitted
Safety phone number for emergencies only
Participants must carry mandatory survival gear including:
-20°F sleeping bag
Insulated water containers
Emergency food
Headlamp and rear light
Shelter (tent or bivy)
Sleeping pad
Land Acknowledgement
The Susitna 100 takes place on the ancestral lands of the Dena’ina Athabaskan people, who have stewarded this region for generations. We acknowledge their enduring relationship with the land and pay our respect to their elders past, present, and emerging.
About Alaska Winter Wilderness Races
Alaska Winter Wilderness Races is the organizing body behind two of the most iconic and demanding cold-weather endurance events in North America: the Susitna 100 and the Little Su 50K. These human-powered races take place each February in the dramatic and unforgiving landscape around Big Lake, Alaska, inviting participants to test their limits in deep winter conditions.
Founded with a passion for adventure and a love for Alaska’s rugged backcountry, the organization offers a rare opportunity to race on snow-covered, marked trails with breathtaking views and constantly changing terrain. Participants can expect snow, ice, wind, and possibly sunshine, sometimes all in one race, as they navigate by foot, bike, or skis through pristine wilderness.
Held each year over Presidents Day Weekend, the Susitna 100 and Little Su 50K are more than races, they are immersive winter expeditions that demand grit, preparation, and a deep respect for nature. Alaska Winter Wilderness Races provides not just a course, but a full winter adventure that attracts endurance athletes from around the world. For those drawn to solitude, snow, and self-discovery, these races offer a truly unforgettable test.
Check out other Alaska Winter Wilderness Races races:
Disclaimer
We make every effort to provide accurate and up-to-date information on Kåduka, but details may change. Please always confirm the latest information on the official race website. See something that needs correcting? Send us a note at [email protected]