Their winning time: nine days, 12 hours and 20 minutes.
Men, women and dogs are pushed to their limits as they cross a landscape of endless ice and snow.
Its organizers call the Iditarod "The Last Great Race." But, perhaps the greatest of all sled dog races was run on the same trails almost 80 years ago.
The drama of that race is recalled in a new book, "The Cruelest Miles," by Gay and Laney Salisbury. They were inspired to find the true story behind a friendly-looking statue in New York's Central Park.
"Laney and I came [to the Balto statue in Central Park] as children," says Gay Salisbury. "We grew up in the area, so we always came climbing up on his back. But, we had no idea it was a true story."
"We thought it was a fairy tale," says Laney Salisbury.
In fact, the tale of Balto, the sled dog, has become larger than life -- even bounding onto the big screen in a Stephen Spielberg film.
The real story takes place back in 1925. It began with nothing more than a child's sore throat -- a common complaint during any Alaskan winter.
With its harbor frozen solid, the little town of Nome was cut off from the world, save for one life-line: a dog trail that carried the mail on a 30 day journey across the frigid interior.
"In Nome, they said there were two seasons: there was winter and the fourth of July," says Gay. "Among all the remote regions and settlements in Alaska, Nome was the most isolated, the most difficult place to live."
"A lot of miners described it as the toughest proposition. There was constantly a 10-knot wind flowing through everything. If a snow came through and a ground blizzard grew, you'd have to plug up every hole in your little cabin. Otherwise, snow would come through the peephole or through your keyhole."
The winter of 1925 was turning out to be one of the coldest on record -- and more and more children began to fall ill with a persistent cough. Then, less than a month after Christmas, Curtis Welch, the town's only doctor, made a frightening diagnosis: diphtheria.
It was a gruesome disease, easily spread from child to child. Diphtheria was known as "the strangler." It killed slowly, choking its victims. Doctor Welch quickly realized he was missing the one thing that could prevent the death of hundreds of children: diphtheria antitoxin.
So, on January 22, Welch issued a telegram -- one that would be read across the country – with an urgent plea to help save the children of Nome.
Airlifting the serum was the town's first hope, just as it would be today. But in the winter of 1925, flying was simply not an option. Nowhere in the entire territory of Alaska were there planes or pilots capable of making the journey.
Nome's salvation would need to arrive -- if it arrived at all -- the old-fashioned way: on four paws.
"The most reliable method was still the old dog team," says Gay Salisbury. That's one of the oldest methods of transportation. It was invented by the Eskimos thousands of years earlier"
So Nome turned to Leonhard Seppala -- reigning champion of Alaskan dog-drivers, known as '"mushers." It was a word derived from the French command "marchon" or "march!"
Seppala was famous for his Siberian huskies dogs -- smaller and more agile than their competitors. In the little Norwegian immigrant, the Salisburys found their story's hero.
"His competitors always said on the trail that he held a hypnotic power over his dogs," says Gay Salisbury. "And they thought that that he was somehow kind of cheating. He would just make one cluck or one click and the dogs would you know just dig into their harness and just pull like they've never pulled before."
Seppala quickly realized that his only course of action was to the only solution was to organize a relay, starting at the railhead-town of Nenana -- stretching 674 miles west to Nome.
Late on January 27, the first team set out. The temperature had dropped to -50 degrees, and as the serum traveled west, conditions would only get worse.
One man hit ice fog, which was a thick mist of ice crystals, and almost didn't make it to his stop. He suffered severe frost bite, and lost two dogs. It is said had no lead dogs left to lead the team, so he moved to the front of the sled, put the harness on, and lead the team the last five miles to the next destination.
In all, 20 teams volunteered to cover the route. Despite their fur parkas and mittens, many of the men suffered severe frostbite. At least half-a-dozen dogs are known to have perished on the trail.
"In that weather, the mail would never of gone through," says Gay Salisbury. "By exerting themselves at those speeds and that temperature, their lungs pretty much burst."
"These were hard bitten men who'd go through anything," says Laney Salisbury. "They'll lose a limb and grin and bear it. But, they lose a dog and they break down into tears."
Pushing dogs past their limit was no easy decision for the mushers. To a man, they knew their lives depended on the strength, and loyalty, of their dogs.
Laney explains, "There's a saying in Alaska, 'You're only as good as your dogs on the trails of Alaska. And your dogs are only as good as his feet.'"
Colonel Norman Vaughan knows more than a little about dogs – as a teenager, he was head musher for Admiral Byrd's 1928 expedition to the North Pole, and later he raced in thirteen Iditarods.
"A good dog is everything," says Vaughan.
If the value of a good dog has proven timeless, so has the media's appetite for a good story. From the moment doctor Welch's telegram reached the lower 48, Nome's plight captured the public's imagination.
"I liken it to Apollo 13, you know, when our astronauts said 'Houston, we've got a problem,'" says Gay Salisbury. "It set the country on the edge of their seat.
"This was one the great first times that the country got to follow a story as it unfolded. With wire technology, they were able to follow the progress every day."
Alaska had a reputation as being an exotic, hard core environment. It was called the "Last Frontier" even then.
"It hit a nerve for every reader in the U.S.," says Laney Salisbury. "Which allowed the story to continue to run."
As if it were scripted for Hollywood, the story of the serum run got more exciting with each passing day. Alaska was hit with the worst winter storm in 20 years. And after mushing more than 150 miles east, Leonhard Seppala nearly missed his rendezvous with the west-bound relay team.
Turning back towards Nome, Seppala faced the crux of the entire journey: He had to choose between crossing the frozen waters of Norton sound, or taking the longer, but safer, coastal route. Uncertain whether his own daughter had been stricken, Seppala chose the shortcut.
"The dog has to understand that the driver is purposely not going to put him in a tight situation," explains Laney Salisbury. "And the driver has to understand that the trail may go left, and the dog will go right. And, the driver has to understand that the dog is doing this for a good reason, and should leave him be. And in that sense, they're both depending on each other for survival."
Blinded by snow and gale-force winds, Seppala's legendary lead dog -- a 12-year-old husky named Togo -- guided his team and the precious serum safely to the next hand-off.
The last leg of the relay was lead by a dog named Balto -- a dog that almost nobody thought was up to the task.
Gay says, "That last 53 miles of the Serum run were under a blizzard almost the entire time. Balto had find the trail. He had sniffed it out. He was able to hold the trail, to hold a straight line in a complete white out.
With Balto in the lead, the serum was rushed into Nome at 5:30 a.m., February 2. The journey, which would have normally taken 30 days, was completed in just over five days.
Doctor Welch immediately put the antitoxin to use: all but five of Nome's children were saved from Diptheria. The race was over.
Or so it seemed. The media was now clamoring for film and photos of Balto, the hero of Nome.
In fact, the rest of Balto's life would be a storm of publicity. He posed for countless photos -- eventually modeling for the statue that stands near William Shakespeare and Christopher Columbus in NYC's Central Park.
While there's no statue honoring Leonhard Seppala's lead dog togo, in 1930, the American Kennel Club paid tribute to his memory by officially recognizing his breed - the Siberian Husky. Today, Togo's direct descendants are still alive and well.
But the serum run of 1925 marked the end of the era of dog-sledding in Alaska. The airplane would soon eclipse its star.
Still, each year, when mushers and dogs run the Iditarod, they are chasing something more than a prize. They are chasing the memory of a time when the hearts of men and dogs were the most powerful engines in the land.