The Iditarod is a long-distance sled dog race across Alaska, run every March from Anchorage toward Nome on the Bering Sea. It begins with a ceremonial start in Anchorage, then the real racing starts from Willow, north of the city. Each musher drives a team of 12 to 16 dogs, and at least five dogs must still be in harness at the finish. The route is 938 miles, so even the fastest teams spend more than a week on the trail, while others can need much longer. Weather directly impacts the race: teams can encounter blizzards, whiteouts, sub-zero temperatures, gale-force winds, and dangerous wind chill conditions within minutes.
From Willow, the trail climbs through Rainy Pass in the Alaska Range, drops into the thinly populated interior, and then works west through tundra, spruce forest, rivers, small towns, Athabaskan and Inupiat settlements, and stretches of sea ice before reaching Nome. The race began in the 1970s as a test of top mushers and dog teams, and it still carries a strong link to Alaska's dog-mushing history. More than fifty mushers and roughly a thousand dogs usually start, with Alaskans making up much of the field but finishers coming from many countries. The Anchorage start draws big crowds and media, while fans elsewhere follow the trackers online and volunteers travel in to help at checkpoints. Libby Riddles was the first woman to win, and Susan Butcher followed with a run of wins that made her one of the race's central figures.