“I call her my steering wheel.”

Martin Buser is on the phone. As a dogsledder living in Big Lake, Alaska, he inhabits a world completely foreign to most city-dwellers. Instead of workdays filled with computer screens and email, coffee breaks and stalled freeways, he has icy winter training runs filled with the panting of dogs muffled by the silence of snow-blanketed trees; the swish of a sled’s runners and the sound of his own breath in the dry air.

The “steering wheel” is Bewitched, a promising lead dog. He has others. Many others. Half of his dogs can take lead, and Buser has in excess of 70 dogs at any given time. He’s a professional musher, and one of the most successful. The athlete and breeder is in that elite crew of perhaps 20 mushers worldwide who make a living from racing sled dogs.

Buser made his name in the Iditarod, the world’s most famous sled dog race. With a course stretching more than 1,100 miles through Alaskan wilderness, the race starts on the first Saturday of March in Anchorage, then finishes in Nome after crossing two mountain ranges. The race was started in 1973 to celebrate Alaska’s sled trail history and reenact a famous run in 1925 in which diphtheria serum was rushed to Nome by sled. Buser has crossed the finish line 23 times, and won the race four times. He also holds the course record, completing the trek in under nine days.

To put his accomplishments in perspective: More people have summited Mount Everest than have crossed the finish line at the Iditarod.

The musher trains hard. Really hard. Twelve hours or more, 365 days a year. Some days, he’ll spend 14-plus hours travelling through “the biggest office in the world.” That’s what it takes to be a contender.

His voice is friendly but self-assured.

“If you don’t do it as committed as I am, you’re not going to threaten me.”

What does it take to win the Iditarod?

“Mostly a lot of mind over matter,” says the veteran musher. He says he doesn’t “have quit” in him, using “quit” like it’s a noun, not a verb.

In race mileage alone, he’s covered enough terrain to equal two circumnavigations of the globe. And over the course of the Iditarod, each of his dogs’ paws will touch the ground two million times. His dogs aren’t much for quitting either.

But winning is never simple, even for champions. The first five or six days on the trail are easy, says Buser. At one point or another, however, you’re going to have to push. Buser pushes himself, he pushes his family (he’s married, with two kids), and he pushes his dogs.

Iditarod Trail Headquarters is located in Wasilla, an hour or so down the No. 3 Highway from Anchorage. Tourists visit the site by the busload. It is, in a sense, the Mecca of mushing.

Chas St. George is the public relations director for the Iditarod. This race is big by any measure: big landscape and big mileage, sure, but also a massive logistical challenge to organize. During the event, St. George says, race vets conduct more than 10,000 checks of dogs; dogs consume 10,000 to 12,000 calories each per day (and you thought your dog ate a lot!); 1,800 volunteers help make the whole thing happen; and the Iditarod website has more than 500 million page views during the event, including 2.5 million new users.

Success at a race in which any one of the top 30 teams has a chance at winning comes down to developing a strategy and sticking with it, says St. George: “You plan your work and you work your plan.”

Every plan is based upon developing a strong team. The dogs are in excellent physical shape, but the competitive nature of this race has forced the mushers to follow suit. Mushing has always been a tough workout, but today’s top racer, says St. George, could be compared to an ultra-marathoner. On uphills, the human team member pushes, and even on the flats, the driver sometimes has to pitch in. Peaking for the race includes developing a bond between human and canine that’s stronger than cement.

Of course, any event in which dogs are worked hard will invite criticism. It’s one thing for a person to decide to push his or her limits, but it’s a different situation when a dog owner encourages his or her dogs to push their limits.

The Iditarod’s chief veterinarian is responsible for protecting the health and well-being of more than a thousand high-performance dogs. For 12 years, that task has fallen to Stuart Nelson, Jr.

“One of my primary goals is to educate the mushers,” he says. In the early days of the race, the relationship between vets and racers was not as harmonious; a cops and robbers scenario, he says, in which mushers felt like vets were trying to pick on them. Nelson has made a concerted effort to change that dynamic. “I get a lot of really positive feedback from the mushers.”

The Iditarod’s health system is “pretty elaborate,” says the vet. Beginning a month before the race, every competing dog has blood work done and undergoes an EKG to test heart function. Then, two weeks from the starting line, each dog must complete a physical exam. In addition, all of the dogs are dewormed and must be micro-chipped. Chips are checked at the start line to make sure the dogs in the harnesses are the same dogs that underwent physical testing.

More than 30 vets work as volunteers for the race. The goal at each checkpoint is to give each dog a quick physical exam. Results are jotted into a “vet book” which the musher must present at the next checkpoint. Mushers are encouraged to look for warning signs that a dog might need to be dropped, such as a change in gait or a loss of enthusiasm.

Dogs die in this race. That’s the harsh reality. The Iditarod’s average over the past few years is two canine fatalities per race. The number has crept up as the field has grown. Causes range from traumatic accidents to physiological problems, such as overheating (the race is in March and these dogs are used to running hard through the dead of winter), ulcers, and myopathy, in which potassium released from the breakdown of muscle causes sudden heart failure.

Tough as the Iditarod may be, another race claims the title of the “toughest sled dog race in the world,” and Julie Estey, executive director of Yukon Quest’s Fairbanks, Alaska, office offers a number of justifications for that boast.

The Yukon Quest race, which has been run every year since 1984, is a month earlier than the Iditarod, when it’s darker and colder. It has fewer than half the checkpoints, requiring mushers to carry more weight and be more independent. And the trail gains and loses more elevation as racers travel between Whitehorse, Yukon, and Fairbanks, Alaska.

The idea for the Yukon Quest, which covers a thousand miles of remote backcountry, was hatched in a bar called the Bull’s Eye Saloon, says Estey. Leroy Shanks, the fellow who came up with it, considered Fairbanks the heart of mushing country, and wanted to create a race that would rekindle interest in the historical goldrush routes from Canada to Alaska.

“We are very fortunate to have a lot of wide open space,” says Estey, explaining why North America is home to the world’s two longest races. It’s wide open terrain that once boasted a much higher population at the end of the nineteenth century when gold was discovered in the Yukon. Settlement was based on waterways, she says, as there were no roads to remote areas. The Yukon Quest route takes mushers to one village that, to this day, still doesn’t have road access in the winter. There are areas in the territory that once boasted thriving towns and are now just a lone heated shack—still a welcome destination for mushers exhausted from a day of battling through swirling snow and deep drifts.

The Quest attracts a slightly different racer than the Iditarod. In addition to mushers that are world class it also includes talented racers who are still living a subsistence lifestyle off the land. Their dog teams aren’t just for racing; these are working dogs who still get worked. Many of the teams don’t have the cash to mount an Iditarod challenge. While sleds these days are typically made of high-tech materials, you can still encounter an old-style ash sled (the old ones are easier to fix on the trail, too). Clothing for a rookie might be “third-hand” army surplus, says Estey.

The Quest is lower in profile than the Iditarod, with a smaller field and a smaller purse, but Estey seems to hold little enmity towards her race’s rival. She says the Iditarod’s success has done an “amazing service” for the sport. And with a recent influx of cash from the Yukon territorial government boosting the first-place purse to $40,000, Estey hopes to see more of the world’s top racers shooting for first place at the Yukon Quest, rather than “top ten” at the Iditarod.

Lance Mackey has won the Yukon Quest two years running. He’s also the only person to win the Quest and also finish in the top ten at the Iditarod in the same year. The end of the former is only ten days before the start of the latter.

Mackey’s tales from the trail are straight out of a Jack London book. “They’re all my buddies—these are my family members,” he says of his team. Being on the trail is “emotional.” Mackey uses the word a number of times. He describes being on “day five with no sleep,” when suddenly it hits you that you might be in the top ten and you find yourself getting teary-eyed. People who’ve never done these endurance races don’t know the “solitude of the whole thing,” he says, or the bond that’s forged when you’re sleeping beside your dogs, and you rely on each other for survival. And sometimes not everyone does survive.

On the Iditarod three years ago, Mackey was two hours into an eight-hour stretch, crossing a frozen lake, when one of his dogs went down and didn’t get up. Ultimately, the dog died. The horror of the situation was compounded by having to place the dead dog on his sled, where two live littermates were already resting, having been dropped from the team. Mackey got the sled moving again but he was devastated.

“My whole world was falling apart,” he says. It took everything in him to keep going. To this day, it remains the worst moment in his mushing career. As far as he’s concerned, two Yukon Quest victories don’t “zero out” the loss of his dog. He takes some comfort in the thought that health defects sometimes strike down even human athletes in the midst of doing what they love.

Mackey rejects the idea that this kind of mushing is inherently cruel. A team that didn’t love to pull wouldn’t be competitive. He acknowledges that in any population of people, there will be “bad seeds,” but his definition of cruelty to animals is a Siberian Husky cooped up in an apartment in Phoenix, Arizona. “[Mushing] is what they’re bred for,” he says, “this is what they love to do.”

Eric Sparling has written for The Globe and Mail, The Toronto Star, Nuvo, ModernDog and numerous other publications.