Getting ready for the Iditarod Trail Sled Dog Race

Justin Savidis dogs await lineup in the musher lot before the official restart of the Iditarod dog sled race in Willow, Alaska. The nearly 1,000-mile (1,600-km) Iditarod Trail Sled Dog Race commemorates a 1925 rescue mission that carried diphtheria serum by sled-dog relay to the coastal community of Nome, which remains the final destination in this 42nd edition of the event.

Nathaniel Wilder/Reuters

Justin Savidis dogs await line-up in the musher lot before the official restart of the Iditarod dog sled race in Willow, Alaska. The nearly 1000-mile Iditarod Trail Sled Dog Race commemorates a 1925 rescue mission that carried diphtheria serum by sled-dog relay to the coastal community of Nome, which remains the final destination in this 42nd edition of the event.