The 40th Iditarod Trail Sled Dog Race kicked off in Willow, Alaska, on March 4 as fans gathered on the sidelines to send off the 66 competitors and their teams of dogs. A ceremonial start was also held on March 3.
Over the next roughly eight days, the athletes will cover about 1,000 miles on their way to Nome, battling sub-zero temperatures and difficult terrain.
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Six former winners are competing in this year's race and, as of Monday morning, four-time champion Lance Mackey of Fairbanks, Alaska, was in the lead, the Alaska Dispatch reports.
Before the start of this year's race, officials were forced to make some last-minute changes to the trail due to harsh weather conditions that could endanger the mushers and the dogs, according to CNN.
Still, near-record snowfall could take a toll on the teams, but Mackey said it's important to remain focused.
"You really have to respect Mother Nature, and Lord knows, she’s been beating up on me over the years," he told CNN. "So, we just have got to take care of the dogs and keep an even keel."
Although the racing in the Iditarod is a prestigious honor, the journey can certainly be brutal on the sled dogs.
In an article featured in the Sacramento Bee, Jennifer O'Connor, a PETA representative, noted that the dogs run about 100 miles a day and can sustain serious injuries over the course of the journey.
Still, many sled dogs have been bred and trained to race, and their owners take special care of the animals, according to the PBS documentary, "Sled Dogs: An Alaskan Epic."
One important precaution is the use of special "booties" which protect the dogs' feet from the harsh weather conditions. The booties are typically changed about every 100 miles, and it's estimated that mushers go through about 2,000 booties during a single trip.
The first 30 racers to cross the finish line will split a $550,000 purse, with the first-place winner taking home about $50,000 and a truck, according to the Associated Press.
Several athletes participate in other dog sled races throughout the year, but at least one racer said "The Last Great Race On Earth" is the most important one of all.
"It is the Super Bowl of mushing ... It is the big one," Brent Sass told the Associated Press.
For images from the 2012 Iditarod, click through the slideshow below.