Sled dog racing (sometimes termed dog sled racing) is a winter sport most popular in the Arctic regions of the United States, Canada, Russia, Greenland and some European countries: it involves the timed competition of teams of sled dogs that pull a sled with the dog driver or musher standing on the runners. The team completing the marked course in the least time is judged the winner. A sled dog race was a demonstration sport at the 1932 Winter Olympics in Lake Placid, New York and again at the 1952 Winter Olympics in Oslo, and once more in the 1994 Winter Olympics in Lillehammer, but it did not gain official event status. Sled dogs (known also as sleighman dogs, sledge dogs, or sleddogs) are a highly trained dog type that are used to pull a dog sled, a wheel-less vehicle on runners, over snow or ice, by means of harnesses and lines. The first sled race recorded in North America by the ‘International Sled Dog Racing Association’ took place in 1908 in Alaska, the ‘All Alaska Sweepstakes’: it ran 400 miles through some of Alaska’s most arduous areas from Nome to Candle and back. Despite their small size and docile nature, the Siberian Huskies breed ended up dominating racing for a decade, capturing some of the most prestigious Alaska racing titles, especially in rugged terrain where the breed was known for their endurance capability. Siberian Huskies were further popularized in 1925 when the city of Nome was stricken with a diphtheria epidemic and medical supplies were urgently needed: in what came to be known as the “Great Race of Mercy,” 20 mushers and 150 sled dogs transported the diphtheria antitoxin 674 miles across Alaska in a record-breaking five and a half days. The mushers and their dogs became instantly famous across the United States, especially the dog that lead the team on the final 55 mile stretch into Nome, a Siberian Husky named ‘Balto’. Today, sled dog races include “sprint” races over relatively short distances of 4 to 100 miles, mid-distance races from 100 to 300 miles, or long-distance races of 300 to over 1000 miles (as in Iditarod). Sprint races frequently are two or three-day events with heats run on successive days with the same dogs over the same course. Mid-distance races are continuous events of 100 to 300 miles. The first two categories are informal and may overlap, to a certain extent. Long-distance races may be continuous or stage races, in which participants run a different course each day, usually from a central staging location. Races are also categorized by the maximum number of dogs allowed in each team: the most usual categories are four-dog, six-dog, eight-dog, ten-dog, and unlimited (also called open). Racing sleddogs wear individual harnesses to which “tuglines” are snapped, pulling from a loop near the root of the tail. The dogs are hooked in pairs, their tuglines being attached in turn to a central “gangline”. The lines usually include short “necklines” snapped to each dog’s collar, just to keep the dogs in proper position. It is unusual ever to see more than 22 dogs hooked at once in a racing team, and that number is usually seen only on the first day of the most highly competitive sprint events. Dogs may be omitted from the teams on subsequent days, but none may be added. Many other rules apply, most of which have been in effect since the beginning of organized dogsled racing in the city of Nome, Alaska, in 1908. Races are organized either as “timed starts,” or “mass start.” In a timed start, teams start one after another in equal time intervals, competing against the clock rather than directly against one another. This simplifies some logistical considerations such as that of getting many teams of excited sleddogs to the starting line simultaneously. In mass starts, all of the dog teams start simultaneously. Mass starts are popular in Europe (organised by ESDRA, the European Sled Dog Racing Association) and many parts of Canada. Some mass start events can have up to 30 teams (300 dogs) start all at once. The most famous long-distance race is the ‘Iditarod Trail Sled Dog Race’, also known as the “Last Great Race on Earth”. The Iditarod is roughly 1000 miles of some of the roughest and most beautiful terrain in the world: the race consists of fierce mountains, frozen rivers, thick forests, and desolate tundras. Each team of 12–16 dogs must go from Anchorage all the way to Nome. Although each musher has different strategies, each team must have certain pieces of equipment, such as an arctic parka, an ax, snowshoes, and boots for each dog’s feet to protect against cutting ice and hard packed snow injuries. Another example of a dog race is the ‘Finnmark Race’, Europe’s longest dog sled race: 1200 kilometers with 14 dogs over 5-6 days across snowy Finnmark (Norway); 160 teams and more than 1500 dogs take part in Finnmarksløpet, a great test of strength and a great winter festival on the roof of Europe.