Iditarod Trail Sled Dog Race the race. More than 50 mushers enter each year. Most are from rural South Central Alaska, the Interior, and the "Bush"; few are urban, and only a small percentage are from the Contiguous United States, Canada, or overseas. Some are professionals who make their living by selling dogs, running sled dog tours, giving mushing instruction, and speaking about their Iditarod experiences. Others make money from Iditarod-related advertising contracts or book deals. Some are amateurs who make their living hunting, fishing, trapping, gardening, or with seasonal jobs, though lawyers, surgeons, airline pilots, veterinarians, biologists, and CEOs have competed. Per rules#1 and
Iditarod Trail Sled Dog Race reveals the results of tests on the dogs. Each team is composed of twelve to sixteen dogs, and no more may be added during the race. At least five dogs must be on the towline when crossing the finish line in Nome. Mushers keep a veterinary diary on the trail and are required to have it signed by a veterinarian at each checkpoint. Dogs that become exhausted or injured may be carried in the sled's "basket" to the next "dog-drop" site, where they are transported by the volunteer Iditarod Air Force to the Hiland Mountain Correctional Center at Eagle River