Iditarod Trail Sled Dog Race differ by less than . The northern route first passes through Cripple, which is from Anchorage, and from Nome (ITC, "Northern"), making it the middlemost checkpoint. From Cripple, the route passes through Sulatna Crossing to Ruby, on the Yukon River. Ruby is another former gold-rush town which became an Athabaskan village. The southern route first passes through the ghost town of Iditarod, which is the alternate halfway mark, at from Anchorage, and from Nome (ITC, "Southern"). From Iditarod the route goes through the three neighboring Athabaskan villages of Shageluk, Anvik, Grayling, and then on to Eagle Island, Alaska. Ruby and
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