My dog sled races along the frozen polar sea of Greenland’s northwestern coast, weaving through a maze of hummocks. I sit wedged against the fur-covered form of a quiet, middle-aged Inuit hunter named Ilanguaq Qaerngaq, who directs the dozen dogs fanned out before us with deft snaps of a 15-foot-long whip. From out of nowhere, a dog from another team—its trace cut or broken—veers in front of us and falls beneath our left runner. Our 11-foot wooden sled, loaded with several hundred pounds of seal and walrus meat, rides over the creature and continues on. Behind us, the dazed dog struggles to its feet, limping badly. I catch Qaerngaq’s eye, but he shakes his head. In a minute, the dog has become a dark speck on the ice behind us. As we set up tents on the sea ice a couple of hours later, I keep a lookout for the injured dog, but it doesn’t appear. I fear it has become a meal for a polar bear or an arctic fox.

That evening, one of our dogs refuses to eat. Julia Bent, a 55-year-old veterinarian from Seattle, examines the animal and wryly prescribes “warm cage rest, IV fluids, a full blood analysis and urinalysis, probably abdominal and chest X-rays, and appropriate therapy based on our laboratory findings.” She gives the dog some Pepto-Bismol, but the next morning as we leave camp, one of the Inuit hunters shoots the animal in the head with his rifle and leaves the body on the ice.

It’s day two of a nine-day dog-sledding trip from Qaanaaq, a town of a hundred or so brightly painted frame houses perched on a gently sloping hillside overlooking Murchison Sound, south about 200 miles to the smaller Inuit village of Savissivik, and I’ve just been given another lesson about the relationship between the Polar Inuit and their dogs in the high Arctic. It’s all business; on the ice, the Inuit have neither the inclination nor the means to care for badly injured or sick canines. And yet the Inuit’s connection to their dogs is one of the world’s oldest and most complex human-animal partnerships, a relationship “as close as a marriage,” as the French Arctic explorer Jean Malaurie noted in the 1950s.

Unlike the Inuit people in Canada and Alaska, who have largely traded dog sleds for snowmobiles, Polar Inuit have maintained their age-old skills of hunting with sled dogs for subsistence, the only circumpolar culture to do so. And because by law no other breeds may be brought to northern Greenland, this remote area and the small enclave that inhabits it have become a sanctuary for the Inuit dog (Canis familiaris borealis), thought to be North America’s only remaining pure aboriginal canine.

I have joined this expedition at the invitation of photographer Layne Kennedy and Paul Schurke, 48, an Arctic explorer and co-owner, with his wife, Susan, of the Wintergreen Dogsledding Lodge in Ely, Minnesota. In addition to Schurke, his 12-year-old son, Peter, Bent and me, our group consists of six other Americans and ten Inuits—including Ussarqak Henson, 66, grandson of Matthew Henson, the African-American who accompanied Cmdr. Robert Peary on his 1909 expedition to the North Pole. We are joining a group of Polar Inuit on a spring hunt for seal, which they prize both for its meat and hide, from which they make clothes. Schurke’s involvement with the Inuit dog dates to 1986 when he and Arctic explorer Will Steger completed the first unresupplied dog sled expedition to the North Pole. On that 56-day trip, says Schurke, their 49 Inuit dogs, which hauled heavy loads over 1,200 miles of fractured pack ice, were like “little Sherman tanks.” The following year Schurke and his wife bought nine Inuit dogs and opened Wintergreen. They now own 60, the largest collection in the United States; each winter he and his guides take about 500 people dog sledding in Minnesota’s northern woods.

Most maps of North America fail to show the extent of Greenland’s northerly reach because of the distortion created by two-dimensional representations of the globe. From a polar projection—as if looking down at the North Pole from above—the northern tip of Greenland resembles a thumb poised to poke out the pole’s eye, coming far closer to it—about 450 miles—than any other landmass. An ice cap nearly two miles thick covers 84 percent of Greenland’s surface and contains so much water that, were it to melt, the global sea level would rise by 20 feet.

Some 900 Polar Inuit inhabit Qaanaaq and five other villages on a narrow, several-hundred-mile strip along the coast. These Inuit live farther north than any other indigenous people on earth. By April, when our De Havilland Twin Otter aircraft lands on the ice runway of Qaanaaq, winter has finally relinquished its hold. Almost 19 hours of sunlight and temperatures that average a few degrees above zero have replaced days of round-the-clock darkness and minus 40 degree temperatures. Murchison Sound, however, still resembles an immense ice rink. Small boats rest on the frozen beach, and dozens of groups of dogs are tied to stakes near them. Near one dog pack lies a partially devoured walrus.

The next morning, we set off with nine hunters—outfitted in polar bear fur trousers—nine sleds and 101 dogs. Qaerngaq ties the traces of his 12 dogs to a pituq, a looped rope about 12 feet long attached to the sled between the runners. The design of the sled itself—two 12-foot-long wooden runners, a platform of planks, and upright handrails at the back—has changed little over the centuries. Wooden boards, however, have replaced driftwood planks and caribou antler handrails, and nylon rope has replaced sealskin thongs. But the sled’s joints are still loosely bound to allow it to move flexibly over irregularities in the snow and ice. And the sled is still strong enough to withstand a crash—after, say, careering down a steep gully—yet light enough to shoot across the sea ice at speeds approaching ten miles per hour.

The dogs run flank to flank in an arrangement known as a fan hitch, in which the traces are equal in length, except for the lead dog’s, which is slightly longer. The fan hitch gives the dogs enough slack to negotiate obstacles in their path.

As we glide across the ice, the dogs’ bushy tails wave like cattails in a freshening breeze. Over the course of our trip, the dogs will provide endless entertainment—a running soap opera of flirtation, tiffs and, in some cases, raw animal aggression. Qaerngaq is the director: he chastises a lazy young male, ties a bootee onto a dog with a cut paw, takes a flagging one out of its traces for a rest. The wind drives their flatulence into our faces. Early on, a pregnant bitch in the sled in front of us delivers prematurely, dropping her newborn pups onto the ice, and our dogs gobble up the tiny, bloody bodies without breaking stride.

These animals are not to be mistaken for more familiar sled dogs, like those that compete in Alaska’s Iditarod race, most of which are Siberian huskies or mixes of other northern breeds. (“Husky” is actually a generic term for several breeds of sled dogs, including the Samoyed, the Alaskan malamute, the Siberian husky and Inuit dog breeds.) Siberian huskies are faster than Inuit dogs, but not as powerful. Inuit dogs are “sturdy, magnificent animals,” wrote Peary. “There is no dog in the world that can work so long in the lowest temperatures on practically nothing to eat.”

Lynn Peplinski, at the Inuit Heritage Trust, in Canada’s Nunavut Territory, tells of one Inuit who returned home after a month-long hunt, his 20-foot-sled loaded with 14 frozen caribou carcasses; 30 dried seal skins; two wooden boxes filled with tools and kitchenware; sleeping skins and tarpaulins; two steamer trunks; two whole seals; a washtub; five 3-week-old puppies; and his wife, their infant child and their two small children under 10. The 14 dogs pulling this load completed the final, 80-mile leg in 17 hours.

The Inuit dog, known as qimmiq in the Inuit language Inuktitut, has soft, dense insulating under fur and an outer coat of longer, coarser hairs, which shed water and snow. Petting the animal’s muscular chest is akin to touching a brick. I’m surprised the dogs aren’t bigger: males reach only 77 pounds, females about 60. The short, compact dogs’ small, slanted eyes suggest a close kinship to the wolf. But the notion of the northern dog as a tamed wolf placed in a trace and forced to pull a sled, as Jack London portrayed them in White Fang, is “an absurd, romantic myth,” says Jennifer Leonard, an evolutionary biologist at the Smithsonian’s National Museum of Natural History. The Inuit dog is no closer to a wolf than is a Labrador retriever. Archaeological evidence shows that dogs were domesticated from wolves in Europe and Asia at least 15,000 years ago, then spread across the Bering land bridge into what is now Alaska with the New World’s first immigrants. Leonard has found no genetic evidence that dogs in the New World ever bred with wolves.

In Greenland, dog remains have been found along with the earliest signs of human habitation. The first colonizers crossed the Bering Strait from Asia and moved across the islands of the Canadian Arctic to Greenland about 4,400 years ago. The Thule, ancestors of the present-day Polar Inuit, came here later from Alaska, in several waves between A.D. 900 and 1500. Archaeological evidence suggests that early Thule people may have used dogs to chase game and to transport meat and supplies over long distances, a significant capability when climactic fluctuations changed the migration routes of their prey.

“A hunter without dogs can be considered a half hunter,” goes a Greenland folk saying. Because the early Inuit had to get by on what they were able to kill, dogs often meant the difference between survival and starvation. During particularly lean times, the dogs themselves were eaten. “It’s entirely possible that dogs enabled those Pleistocene hunters to colonize the New World,” says Leonard.

Viking explorers came to Greenland just before the Thule people. Under Erik the Red, they colonized southern Greenland during a time of relatively mild climactic conditions. But when the weather grew colder in the late 14th and early 15th centuries, says UCLA biologist Jared Diamond, the Norsemen “starved to death amid an abundance of ringed seals, fish and whales that only the Inuit hunted.” The Inuits survived. They had better boats in the form of kayaks and umiaks, better weapons, with toggle harpoons and bladder floats, and, thanks to their dogs and sleds, far better range.

One afternoon four days into our trip, we are zipping across the ice near a series of high cliffs when one of the dogs pulling our sled suddenly throws its nose in the air and turns his head to the right. Another dog does the same. Then another. We scan the horizon in that direction but see only whiteness. Then, after a couple of minutes, Qaerngaq points out two distant dark spots. We turn toward the inert brown shapes and, ten minutes later, stop about 200 yards shy of a pair of seals resting near a breathing hole. Another Inuit hunter, Frank Angmalortoq, draws up on his sled and pulls out a 3- by 3-foot piece of white cloth stretched over a frame of wood mounted on a pair of small skis. The dogs from both teams lie down and wait quietly as Angmalortoq walks carefully toward his quarry behind the snow-colored blind. Within 50 yards of the seals, he lies down, his .222 Remington poking through the blind, and crawls closer. At the sound of the first shot, the dogs take off toward the seals in a furious surge of energy. I barely jump back onto the sled in time.

Angmalortoq has killed two 300- to 400-pound bearded seals. Through holes he cuts into flesh on their heads, Qaerngaq attaches the traces of our dogs, who drag the seals away from the breathing hole toward thicker ice. The other sleds join us, and the hunters butcher both animals in about 45 minutes, load the large squares of meat onto the sleds and leave the blubber behind.

The work has turned the ice scarlet and filled the air with the aroma of fresh meat, which I would think would drive the dogs wild. But they sit silently. Only later will the Inuit hunters feed them, cutting off hunks of the now frozen meat and throwing one piece to one dog at a time, a technique that prevents the larger ones from poaching food from the smaller. We dine on the seals’ raw intestine and strips of meat cut from along the backbone, which tastes surprisingly good, though fishier than any game I’ve tried before.

On day eight, just north of Cape York, Qaerngaq tells us not to wander off alone—polar bears. We’ve seen their dinner-plate-size paw prints in the snow. At night, the dogs are tied into position to form a living fence around our tents and sleds, a formidable warning system. While our sleep is interrupted on several occasions by the whines and growls of male dogs trying to get at females, no bears approach.

Cape York’s several-hundred-foot-high bluff is famous in the annals of exploration as one of Peary’s bases for Arctic exploration. It was near Cape York that he found three pieces of an immense meteorite. (For centuries, the Inuits used these meteorites as a source of iron for tools.) He took all three pieces and sold them to the AmericanMuseum of Natural History in New York City.

Qaerngaq and Ussarqak Henson can wield a whip, or iperaataq, with a precision a fly fisherman might envy. Aflick of the wrist lands a precise blow to the flank or rump of a dog or a crack above the ear, encouraging it to pick up speed or change directions. Arctic explorer Jean Malaurie observed that “a good driver can strike within one-sixteenth of a square inch of what he aims at.” But more often, our hunters guide the teams with voice commands. Schurke describes once watching a hunter command a team of dogs to stay put while he worked his sled down the face of a precipitous, mile-long glacier. Only when he shouted a command from the glacier’s base did the dogs begin their own descent. The hunter was even able to guide them around crevasses with voice commands.

Recently, Harvard University anthropologist Brian Hare and his colleagues have demonstrated that dogs interpret human voice and body language far better than chimpanzees or wolves. He speculates that this ability has been developed through selective breeding of dogs by humans over the millennia.

Even so, I notice that Qaerngaq is never without his whip. Once I saw him wade into a canine dispute swinging the wooden whip handle. The dogs separated immediately. Bred to attack polar bears, the dogs can be dangerous. Children are warned not to go near them. I met a 12-year-old girl in Savissivik whose face had been terribly disfigured by a dog attack. When Inuit dogs reach the age of about 8 months, they are placed in a harness in which they’ll spend the rest of their lives. Many Inuit knock out some of their dogs’ molars or file down their canine teeth so they won’t be able to chew their harness and escape. If a dog does break its tether in Qaanaaq, the owner has only two hours to retrieve the animal before it may legally be shot. Concern in Greenland over the Inuit dog’s temperament has led to a ban of the animal below the Arctic Circle, about where the sea ice ends. Norwegian Arctic explorer Otto Sverdrup summed up the contradiction of the Inuit dog when he wrote in 1904 that it is “the warmest breath of civilization” but also the “wildest breath of Nature.”

in 1776, the Danish government established Greenland as a protectorate and closed its borders to trade in the belief, says Rasmus Ole Rasmussen, a professor of North Atlantic regional studies at Denmark’s RoskildeUniversity, that Greenland should be “kept more or less isolated from the outside world in order to preserve the traditional culture.” (The ban was not lifted until 1950.) Asimilar logic was applied to snowmobiles, which the Danish government banned for use in hunting in northern Greenland in the 1970s.

Because of the snowmobile ban, the Inuit dog population in Greenland remains robust—about 30,000 animals. In contrast, by the 1970s in Canada, says Ken MacRury, a longtime sled driver who wrote his Cambridge University master’s thesis about the Inuit dog, the snowmobile’s popularity had reduced the number of Inuit dog teams to a handful; there were none in Alaska or in Canada west of Victoria Island. Today, there are only about 100 purebred animals in Canada and fewer than 150 in the United States.

In 1979, Denmark granted home rule to Greenland, and in 1988 and 1998 the Inuits allowed licensed bird and musk ox hunters to use snowmobiles. As a result, says Rasmussen, there has been a “reduction in the total number of sled dogs during the last few years by at least a third.” He thinks the ban will soon be lifted in its entirety. If so, it will be to the dismay of some Inuits. “Hunting is a part of our real life, and using dogs is the most sustainable way to do it,” says Aqaluq Lynge, president of the Inuit Circumpolar Conference-Greenland, an Inuit advocacy organization. Most of the Inuit hunters on our trip—at least the older ones—want nothing to do with snowmobiles.

Even if the ban against them is lifted, eco-tourism may keep dog sledding alive. And, says Rasmussen, there will always be traditionalists who choose to work the dogs, much as some farmers prefer old-fashioned, chemical-free methods of growing crops.

On the last ten-mile stretch of our trip, with a few dozen houses of Savissivik barely visible in the distance, the wind whips across the ice, and the sky shines a blinding blue. Without a word from the hunters, our dogs and those of another sled begin pulling furiously in their harnesses. We race across the sea ice, hunters, visitors and dogs all straining to beat the other sled. Our team pulls ahead, then the other sled overtakes us. Though we lose the race, we feel exhilarated, not only from the speed and the competition, but by the thrill of dog and human working together, as we have for many thousands of years.