Iditarod Trail Sled Dog Race early in the 20th century. The main route of the Iditarod trail extends from Seward in the south to Nome in the northwest, and was first surveyed by Walter Goodwin in 1908, and then cleared and marked by the Alaska Road Commission in 1911 and 1912. The entire network of branching paths covers a total of . Except for the start in Anchorage, the modern race follows parts of the historic trail. The trail is composed of two routes: a northern route, which is run on even-numbered years, and a southern route, which is run on odd-numbered years. Both follow
Iditarod Trail Sled Dog Race dogs are identified and tracked by microchip implants and collar tags. On the trails, volunteer veterinarians examine each dog's heart, hydration, appetite, attitude, weight, lungs, and joints at all of the checkpoints, and look for signs of foot and shoulder injuries, respiration problems, dehydration, diarrhea, and exhaustion. When mushers race through checkpoints, the dogs do not get physical exams. Mushers are not allowed to administer drugs that mask the signs of injury, including stimulants, muscle relaxants, sedatives, anti-inflammatories, and anabolic steroids. , the Iditarod claims that no musher has been banned for giving drugs to dogs. However the Iditarod never