The last thing Joe Redington Sr. remembered before falling asleep that night was passing Old Woman, a rocky bluff halfway between Kaltag, a fishing town on the Yukon River, and Unalakleet, the first Eskimo village on the Bering Sea coast. With 800 virtually sleepless miles behind him, Redington, 66, slumped forward as his 17 dogs pulled him easily over the firm, packed trail toward Nome, 300 miles away. His feet were planted on the sled's runners, his hands instinctively gripping its handle, when the tree branch smashed into his face. It felt like hitting a wooden I beam at 10 mph. Dazed, he watched from the snow as his dog team disappeared into the darkness, and he felt the blood warm his face. "I ducked that branch every year for 10 years," said the veteran musher later, shaking his head. "I couldn't see anything. I thought my nose was broke for sure, but I crawled up the trail 'bout a quarter of a mile after the dogs. I anchored 'em to a tree and went back to find my headlamp." Redington, who dropped from second place to seventh as a result, admitted, "The race never did go right after that."

Alaskans, who relish their role as America's last frontiersmen, have dubbed the annual Iditarod Sled Dog Race "the last great race," and their pride in it has good cause. It is an almost masochistic test of endurance and survival: 1,131 punishing miles along the old Iditarod trail, over which dog teams carried the mail and freight to Nome during the turn-of-the-century gold rush. From Anchorage on the southern coast, the trail crosses two mountain ranges (the Alaska and the Kuskokwim), traverses three cultures (white, Athabascan Indian and Eskimo), cuts down the mighty Yukon River, up the rocky Bering Sea coast and finally across ice-choked Norton Sound to Nome. If you drove a dog team from New York to Kansas City, you would cover about the same distance but miss much of the pain. Six hundred and seventy-four of these miles became legend in 1925 when 19 dog mushers relayed serum from Nenana to Nome to quell an outbreak of diphtheria. Now Iditarod racers, who battle fatigue-induced hallucinations, angry moose and howling storms, must sign in at 27 checkpoints along the route, where dog food and human provisions await them. "You have to be super tough physically and mentally to run this race," says Joe Redington. "How you've lived determines more how you'll do. If you'd worked at a typewriter and came out to do this, you'd have a tough time. But if you'd worked driving spikes on a railroad, you'd probably do good."

The Iditarod is more than a team effort between a tough man and tough dogs. It is a journey on a rickety, wooden time machine, a trip into uncharted, frozen dimensions of geography and consciousness. Afterward, competitors say, you can see every mile of the Iditarod etched on a man's face.

Front Street in Anchorage took on the atmosphere of a seedy carnival last month as 67 teams lined up amid blaring loudspeakers, cheering crowds, blinking traffic lights and howling dogs straining at their harnesses to be off. The top contenders were the Mario Andrettis of dog mushing, with teams tuned like Formula 1 racing machines: Rick Swenson, 32, four-time winner of the race and the only person to win it more than once; Susan Butcher, 28, an Alaskan superstar who took second in 1982, and the only woman to ever finish in the top five; Larry "Cowboy" Smith, 41, a moody fur trapper and burned-out rodeo rider from the Yukon Territory; Rick Mackey, 30, last year's winner and son of 1978 champion Dick Mackey; and Redington, who used to pull twisted pieces of wrecked planes out of the bush with his dog teams and who, with a local historian, came up with the idea for the Iditarod in 1964. These teams had started training as early as August in bush villages like Eureka, Clam Gulch and Teller, pulling wheeled carts over bare ground. The dogs were conditioned like marathon runners and bred to pull a sled until they dropped. Most of the top mushers had corporate sponsors (Tang, Alpo, Arco) to pick up most of the $30,000 cost of running the race. The winner would take home $24,000. The next 19 would split the remainder of the $100,000 purse.

But there were rookie adventurers too: Kari Skogen, a willowy 20-year-old blonde from Norway; Rick Atkinson, 29, a mountaineering instructor who had driven dogs for a British Antarctic survey; Armen Khatchikian, 28, who won a contest in Italy to pay his expenses for the race; and Rick Armstrong, 40, a weekend musher from Ohio who moved to Alaska in 1981 after reading about Emmitt Peters, an Athabascan Indian who won the Iditarod in 1975. "It's a dream I had," said Armstrong. "It's cost me $18,000 this year, and I'm $2,500 in debt. Getting to Nome is my only goal. I'm a tourist. I want to see the country."

The dog teams raced out of Anchorage on March 3, grateful to leave the city behind. Mushers shouted at their teams, "Gee!" (right), "Haw!" (left) and "Get ahead!" (Never do they yell "Mush!" a bastardization of the order French Canadian trappers gave their dogs, "Marche!") The teams of 12 to 17 dogs moved west under the shoulder of majestic, 20,320-foot Mount McKinley. The temperature was an unseasonably high 34° as they trotted past Knik, Rabbit Lake and Skwentna. "It's too damn hot," complained Susan Butcher, eyeing her dogs' lolling tongues and steaming thick fur. "Ideal temperature for them is minus 20." The leaders inched their dogs across the snow-covered bogs of Ptarmigan Flats toward Rainy Pass, lost somewhere above in the white fog and snow.

Cowboy Smith's sled was the first to come cascading over the pass into Rohn, a CCC cabin about 50 hours from the start. Whistling to his dogs to keep on, he cradled one arm. "Cracked it bouncing off the rocks," he growled. "Broke my dang sled too. I can fix it. Taught a guy to fly a plane once in the air while I wired the door shut."

As mushers trickled into Rohn that night, the true race began to take shape—the psychological cat-and-mouse game that would play havoc with their minds for the next 1,000 miles. Rick Swenson swaggered into the cabin where other bleary-eyed mushers stared into their soup. "Think I'll take my 24-hour layover here," he challenged casually. All eyes darted to his ruddy Scandinavian face: Less experienced mushers would ape his strategy all the way to Nome. Looking around disdainfully, Swenson turned on his heel. "Got to feed my dogs." An hour later he had sneaked out of camp; by midnight he was 10 miles on his way to the next checkpoint—Nikolai, a Russian Orthodox village 70 miles away. His absence prompted other, panicked departures. "That Swenson," snickered Cowboy Smith. "He has them so psyched out, they'll do whatever he wants."

Before sighting the blue, onion-domed church at Nikolai, however, the mushers would have to cross the notorious Farewell Burn, ravaged by a forest fire in 1978. The Burn is an obstacle course of open water and charred stumps of black spruce whose shadows make it hard to see the gaping trenches and holes.

In Nikolai the wind howled at 50 mph as the villagers waited for the first musher. The town has no running water (although there are four cable TV channels), and the only way to get there is by snow machine, plane or dog team. "The Burn is a strange place," mused Jeff Stokes of Nikolai. "Natives here still consider it sacred ground. Their forefathers died out there fighting the Cook Inlet Indians."

Rookie Dan Cowan's eyes were bloodshot, his face pale under wind-burned skin, as he straggled into town after the leaders. Sensory deprivation and lack of sleep were taking their toll. "I was going along fine out there, but I was real tired," Cowan said, his voice rasping. "I looked over to my right in the dark and I saw a big pink building. I blinked my eyes a couple of times and looked again. There it was, a couple of stories high. I told myself to count to 10. If I saw it again, I decided, I'd just go home." On his next look, it was gone.

Susan Butcher was the first into McGrath, a town of 600 whose Main Street is an airstrip. Activity in the town revolves around McGuire's tavern, a dank bar that reeked of stale beer and cigarettes. "We have three holidays here," said Mike Harrington, Mayor of McGrath and formerly of Queens, N.Y., who sported a three-day stubble. "Christmas, Easter and Iditarod."

But no one stayed long in McGrath. They raced on to Cripple Landing, the halfway checkpoint on the Innoko River, where $2,000 in silver waited for the first musher. Surprisingly, a commercial fisherman named Dean Osmar passed Butcher and got there first, around midnight. A man of few words whose parents moved to the frontier to homestead when he was 2, he had mushed dogs for only five years and looked shell-shocked as he was presented with a bucket of silver coins in a surreal ceremony under the glare of TV lights in the Alaskan bush. "Got to get going," Osmar mumbled.

Some 120 miles later Osmar was still in the lead at Ruby, the first village on the Yukon River. The race had become a grim fight to make correct decisions in the face of exhaustion; the wrong trail would spell disaster. Pacing the dogs was critical. Five hours running. Four hours off. Three hours running. Two hours off. Past Galena, an Air Force base from which F-15 fighters take off after Soviet planes. Past Nulato, past Kaltag. Osmar, still in front three-quarters of the way to the finish, was forced to rely on his well-trained lead dogs, Bullet and Red, to find the trail without the scent of another team. "You look out ahead of you, and your mind is fighting to sleep," said Osmar. "The dogs begin to take on weird shapes. The team expands and contracts. You begin to hear things. The dogs lean against each other while they're running. Pretty soon a couple of them will fall asleep and stumble. That'll wake them up and they'll run some more."

Good lead dogs have been known to break under the pressure. "Sometimes a leader will take the responsibility just so far," explained Joe Redington. "Then he might crack, like a nervous breakdown. Them times you better hope you have another good leader."

By the 10th day Osmar had reached the coastal town of Unalakleet, an Eskimo village whose name means "Where the wind changes and blows from the east." From here it was a 300-mile sprint to Nome. He had extended his lead to eight hours over the nearest competitors, Joe Garnie, an Eskimo, and Susan Butcher. (By this point, 19 racers had scratched.) Osmar followed the Bering Sea coast 40 miles north, out on the open ice where mushers behind him would slip into channels of open water. At Shaktoolik, he felt panic when a village elder told him the trail had not been marked to the next checkpoint. Osmar would have to find his own way to frozen Norton Sound; two years earlier a musher had gotten lost in the same area and suffered severe frostbite. "Just head toward the big rock," an Eskimo told Osmar, pointing out into the darkness.

Two days later, at a few minutes before midnight, the fire alarm in Nome began to whoop and the local dogs set up a yowling welcome. Dean Osmar was coming down Front Street into the long chute that led to the finish. Four thousand cheering people lined his path, many of them well-wishers who had staggered out of the Board of Trade Saloon, the Bering Sea Saloon and the Breakers Bar. Out of the darkness of 1,131 miles, Osmar led his exhausted team into glaring lights under the 30-foot banner that carries the words: "End Iditarod Trail." Osmar's time: 12 days, 15 hours, 7 minutes, 33 seconds from Anchorage. "My dogs. They did it for me," he said quietly.

One hour and 38 minutes later Susan Butcher crossed the line, waving to the cheering crowds. She had made up seven hours in two days, but she had run out of time.

More than two days later rookie Rick Armstrong of Ohio trudged up the chute at 2 a.m., leading his dogs. Only a few friends were on hand to acknowledge his 18th-place finish, but he had made it in the money: He would win $1,300 and an Iditarod patch to sew on his jacket. His face puffy with windburn and fatigue, fingers swollen to the size of big cigars, Armstrong hugged his girlfriend. The adrenaline was still pumping. "I was out there with Emmitt Peters, the guy I read about 10 years ago," he said excitedly. "We were at the top of Topkok hill last night, coming toward Nome. We stopped together for about 15 minutes to rest the dogs. He was facing in one direction, munching on his dried salmon. I was sitting on my sled looking out over Norton Sound. No photographic film could have captured how crystal clear and cold it was. The northern lights were playing red and green right above us in the sky. Here we were, the man from Ohio who had dreamed about this race and the man from interior Alaska who had mushed dogs all his life.

"And he was as struck by it as I was."