Another annual edition of one of the most grueling (and definitely coldest) events just wrapped up. Our daily fun facts take a dive into this amazing race. 

• In 1925, there was an outbreak of diphtheria in Nome. A serum was available in Anchorage, but a blizzard prevented pilots from flying out, and seaports were frozen over. So, organizers set up a relay of dog teams among the villages along the old Iditarod Trail, used for centuries by native Alaskans. Twenty volunteer “mushers” and their dogs transported the serum to Nome in just six days.

• In 1964, Alaska began preparing for its centennial celebration in 1967—marking 100 years since the territory was purchased by the United States. Dorothy Page, chairwoman of the centennial for the cities of Wasilia and Knik, came up with the idea to spotlight the history of the Iditarod Trail, including the Nome serum run, and the role of dog teams in general. Page’s idea: a dogsled race spanning the entirety of the Iditarod Trail. After test races in 1967 and 1969, the Iditarod was run for real in 1973.

• An average of 16 dogs are on each team. Each dog is fitted with microchips and collar tags if they get lost in the wilderness, their feet are protected by booties, and there are veterinarians available at every checkpoint (along with lots of donated dog food). If a dog does get injured during the race, it’s airlifted from a checkpoint back to the Eagle River checkpoint. There, inmates from the Hiland Mountain Correctional Center take care of the dog until its musher returns.

• The temperatures on the trail can drop as low as −50 °F, with winds as high as 50 mph. Not only does that make for brutal conditions, but the snow and wind can obscure the trail and trail markers. In 1976, musher Norman Vaughn (who drove a dogsled in a 1928 South Pole expedition) went off the trail after a blizzard and was lost for five days.

• In 2005, 18-year-old Dallas Seavey became the youngest person to race in the Iditarod. He’s since won the whole thing three times, in 2012, 2014 (with a new record time), and 2015. His streak was broken in 2013 by Mitch Seavey, a previous winner…and Dallas Seavey’s father.

• First prize in 2015: $69,000 and a new Dodge Truck.

• The Iditarod is one of a handful of major sporting events in which men and women compete side by side. In 1985, Libby Riddles became the first woman to win the Iditarod—a victory that came in part because she was the only musher who chose not to sit out a particularly bad blizzard.