The Yukon Quest is an annual 1,000-mile sled dog race between Fairbanks, Alaska, and Whitehorse, Yukon, Canada. It is run in early February, the heart of winter in the Northern Hemisphere, and was created in the mid-1980s to replicate the difficulty of the Iditarod Trail Sled Dog Race but with much less of the help Iditarod mushers are allowed. Competitors travel through roadless areas of Alaska and the Yukon, including along extended stretches of the Yukon River, in temperatures that plunge to as low as -60F. Racers deal with deep snowdrifts, wind-blown summits, and stretches of tundra scoured of snow by extreme gusts. Though less known than the Iditarod, the Yukon Quest has been considered a more difficult sled dog race, and the ultimate long-distance mushing accomplishment — winning both races in a single year — has been done by only one person: Lance Mackey. Racers have been injured — though none yet killed — during its running, and on average fewer than half complete the race. Nevertheless, it remains one of the three biggest sled dog events in Alaska each year and attracts the best mushers from around the world.