Sled Dog Day, also known as National Sled Dog Day, is observed worldwide every February 2 to celebrate the loyal and hard-working sled dogs that were historically essential for transportation in the Arctic region. This date commemorates the 1925 serum run to Nome, which delivered diphtheria antitoxin to save the town from an epidemic. During this event, 150 sled dogs and 20 mushers transported the antitoxin over 1,085 km in just five and a half days, with notable dogs like Balto and Togo gaining fame for their roles. Although sled dogs are now rarely used for transportation, they remain popular in racing events and recreational activities, with the Iditarod Trail Sled Dog Race being the most famous. Sled Dog Day serves as a reminder of the historical significance of these animals and their contributions to exploration and community support in remote areas.