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Melissa Stewart's team competes in the official restart of the Iditarod, a nearly 1,000-mile sled dog race across the Alaskan wilderness, in Fairbanks, Alaska. REUTERS/Nathaniel Wilder

Every year dogsledders gather in Alaska to take part in the Iditarod Trail Sled Dog Race, a 1,150-mile race that sees between 60 and 100 teams participate in the grueling annual event. Started in 1973, the race covers a journey from Anchorage to Nome.

While Iditarod is a city, a river and a trail, the race came into being when musher Joe Redington, Sr. created the long-distance race to keep Alaska dog sledding tradition alive. The race was moved to Fairbanks, 359 miles north of Anchorage, in 2003, after the trail near Willow was affected by warm weather conditions, the National Geographic reported.

When the first Iditarod took place in 1973, the teams took around 20 days to complete the race, but now the average time to finish the race is about 10 days.

Read: Is The Iditarod Humane? Alaska Sled Dog Race Slammed For Animal Cruelty By Critics

Since the early 1990s, only northern dog breeds like Siberian huskies and Alaskan malamutes are allowed to participate in the Iditarod as they are more suitable for the extreme cold. While every team starts with 16 dogs, they must finish the race with at least six dogs.

Many critics have slammed Iditarod for animal cruelty but organizers say the northern dog breeds rule is meant to protect dogs that aren’t made for cold-weather racing.

The participating dogs are required to keep eating while they are on the trail and are usually fed frozen snacks like meat, fish or dog food. They are also fed hot meals when they stop at checkpoints. Dogs are supposed to wear booties — not for protection from the cold — to protect their foot pads from the harsh terrain.

Here are pictures and videos from the 2017 Iditarod, also referred to as “the last great race,” as the dogs and mushers race along the Alaskan snow:

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Justin High, a rookie, competes in the official restart of the Iditarod. REUTERS/Nathaniel Wilder
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Trent Herbst competes in the official restart of the Iditarod, a nearly 1,000 mile sled dog race across the Alaskan wilderness, in Fairbanks, Alaska, March 6, 2017. REUTERS/Nathaniel Wilder
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Cindy Abbott competes in the official restart of the Iditarod. REUTERS/Nathaniel Wilder
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Alaska Governor Bill Walker rides with John Baker's team in the ceremonial start to the Iditarod. REUTERS/Nathaniel Wilder