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 where they are taken care of by prison inmates until picked up by handlers or family members, or they are flown to Nome for transport home. According to Iditarod veterinarian Dr. Stuart Nelson, Jr., "Reasons for dropping dogs are numerous. Attitude problems, fatigue, illness, immaturity, injury, being “in heat,” lack of speed and musher strategy, are the more common ones." The dogs are well-conditioned athletes. Training starts in late summer or early fall and intensifies between November and March; competitive teams run before the race. When there is no snow, dog drivers train using wheeled carts or all-terrain vehicles set