<P> The Yukon Arctic Ultra is a series of non-stop multiday races that take place concurrently beginning in Whitehorse, Yukon at the beginning of February each year . The marathon, 100 / 300 / 430 mile races follow the course of the Yukon Quest . The longer races have three disciplines: mountain bike, xc - skis or foot . The race is billed as the toughest ultramarathon in the world where the temperatures can drop to - 50 degrees plus wind chill . The race was founded in 2003 and has run every year since except 2010 . </P> <P> The race is self - provisioned . While the organizers provide trail guides, there is a real risk of frostbite and amputations . </P>

Where is the montane yukon arctic ultra held each year