
Winter fatbike ultra event and registration dates are posted for most of next year's events in our region. If you're new to winter ultras or are curious about taking on one of these challenges, check out the races overviews and important dates below.
Winter fatbike ultras quite possibly take more planning and preparation than any other cycling discipline. On top of race planning, you'll generally need to also complete a qualifying event in order to just register, to demonstrate that you have the experience and physical ability to compete in sub-zero temperates for days at a time with no support.
Here we outline the 5 regional winter fatbike ultra races, their registration dates, qualifying events, as well as a few bonus events just for fun.
Never Done a Winter Ultra Before?
We recently put together a 3-part "Introduction to Winter Fatbike Ultras" series with Jamison Swift where you can learn all about resources, races, gear, risks, how to stay warm and plan the food you'll need to bring.
Part 1: Races, Risks, & Resources
Part 2: Logistics of Food, Water, Gear, & Staying Warm
Part 3: Tips from Seasoned Ultra Veterans

If you're brand new to winter fatbike ultras, the St. Croix 40 Winter Ultra is the perfect place to start. It's a shorter course that takes place overnight and requires you to carry (and practice using) the same gear you'll need for longer races like Arrowhead, Tuscobia, and more. Then if you have dreams of completing a race like Arrowhead, check out our resource, "What Does It Take to Complete Arrowhead 135" where we hear from 4 incredible athletes who have raced and completed it a combined 30 times.
Here is a list of our region's winter fatbike ultras, their race dates, and registrations dates you'll want to put in your calendar. If you wait until winter to register, you'll be too late as most winter events have registration open in August or September and fill up fast.
Make sure to do your research and get familiar with any relevant qualifying events you'll need to complete as well as required gear.
St. Croix 40 Winter Ultra - Hinckley, MN
Race Date: Jan 13-14, 2024
Registration Date: August 15, 2023

The St. Croix 40 is a short course winter ultra for those who are curious about longer winter ultras in the spirit of the Arrowhead 135 or Tuscobia 160.
Participants travel roughly 40 miles through St. Croix State Park on foot, ski, or fat bike, carrying all essential survival gear through a cold Minnesota night.
Not only will you need to traverse the 40-mile course distance, but you will also need to prove that you can utilize your survival gear at two different points in the race. These skill tests will help prepare you for bigger challenges in the future.
Arrowhead 135 - International Falls, MN
Race Dates: Jan 29-31, 2024
Registration Date: September 1, 2023
The Arrowhead 135 is an ultra-endurance race that takes place in International Falls, Minnesota. It's a non-stop, self-supported race, where participants have to carry all their equipment and supplies for the duration of the race, including food, water, and shelter. The race follows the Arrowhead State Trail from International Falls, Minnesota to Tower, Minnesota, a distance of approximately 135 miles.
It takes place in the dead of winter when temperatures can drop to well below zero degrees and blizzard conditions are not uncommon.
Participants can choose to compete on foot, on a bike, or on skis, and they have up to 60 hours to complete the race. The race is known for being one of the toughest winter ultras in the world.
Qualifying activities for bikers:
Complete a prior Arrowhead 135, Tuscobia 160, Susitna, or similar race.
Finishing 24 hour bike race, with minimum of 100 miles completed for off-road, or 200 miles on road.
A race in winter conditions improves your odds of being selected and surviving.
Tuscobia Winter Ultra - Rice Lake, WI
Race Dates: Usually Around Last Week of December
Registration Date: August 1, 2023
The Tuscobia Winter Ultra is a run, bike or ski event held on the Tuscobia State Trail in Northern Wisconsn in the middle of winter between Rice Lake and a few miles east of Park Falls, WI. Participants can compete in the 160-mile or 80-mile event.
160-mile participants must have previously completed one of the following events:
Tuscobia 160/150/80/75 mile
Arrowhead 135 mile
Iditarod Trail Invitational (any distance)
Actif Epica (any distance)
Fat Pursuit 200 km / mile
Frozen Otter 64 mile
Susitna 100 mile
White Mountains 100 mile
Yukon 100/300 mile
6633 Arctic Ultra
Alaska Mountain Wilderness Ski Classic
Rovaniemi 150/300 km
The Drift 100
Polar Roll Winter Ultra - Upper Peninsula, MI
Race Dates: Feb 19, 2024
Registration Date: Nov 5, 2023
2023 was the first year of the Polar Roll Winter Ultra. As such, you can expect some similarities from the first year as well as a few enhancements coming into year two for 2024. Here is the description from the inaugural year: The ultimate U.P. fat bike experience. Here’s what we can share: It’s going to be at least 100-miles. The course will utilize a variety of groomed and not groomed surfaces. A required gear list will be available no later than 12.01.2022. Tracking beacons will be provided – participants will be required to use one. Family and friends will be able to keep tabs on your real-time progress online. Participants should be fully prepared to be self-supported. Spots will be limited to 50 participants.
The course will traverse remote tracts of land and trail inaccessible to anyone not on a snowmobile. The weather is notoriously unpredictable and dangerous. We will reserve the right to vet registrations as they are received. Gordon Gearheart will be commissioned to create a finishers award worthy of the effort required to finish.