By Will Steger with Paul Schurke

Times Books. 339 pp. $19.95

THERE IS no doubt as to who first reached the South Pole: the Norwegian Roald Amundsen in 1911. The North Pole is a different matter. For one thing, it lacks a fixed surface, where one might plant a flag or build a cairn. Antarctica is a continent, but the Arctic is a sea, mostly frozen and always on the move, and the icepack atop the polar point one year may have strayed several miles south (the only direction possible) by the next.

In addition to this inherent verifiability problem, history has thrown up rival claimants, both American and each with weaknesses in his case, for the North Polar prize. Frederick Cook claimed to have reached it in 1908, Robert Peary in 1909. Cook was unable to produce navigational records of his journey, and Peary's final sprint -- in which he and his men logged 25, 30, 40 miles per day -- seemed too good to be true. Though most judges have found for Peary and his unsung assistant, a black man named Matthew Henson, there is lingering uneasiness in court.

It was partly in order to dispel these doubts that two Minnesota wilderness outfitters, Will Steger and Paul Schurke, mounted their spring 1986 polar expedition. They and their six companions relied on dogsleds and got along without resupply. But for the fiberfill in their sleeping bags and the Velcro tabs on their parkas, theirs might have been a trek from the century before.

The literature of exploration is uncommonly blessed with stylish writing and probing examinations of humans under stress, and North to the Pole adds to the lustre. Steger excels at framing the challenges of travel on icepack. "Moving sleds over the polar snow," he writes, was like dragging boats over boulder fields." It was hard to decide which were more taxing -- the pressure ridges, where heaved-up chunks of ice barred the way, or the valleys in between, where snowdrifts lay waiting. Only when the expedition happened upon leads -- fissures in the icepack that had filled with water and frozen over -- was progress smooth.

Steger and company were pawns of climate. They needed the "mild" temperatures and constant sunshine of the Arctic spring to survive (a sunny, windless 50 degrees below Farenheit day was a godsend) but had to worry about the onset of melting, which might sink them. One afternoon the temperature rose to "a balmy" 30 below," and the expedition halted at the edge of an open -- i.e., melted -- lead. They turned civil engineering corps, rolling blocks of ice into the lead until a floating bridge spanned the gap. Canadian Brent Boddy readied his sled. "The dogs, sensing the danger, gingerly stepped from one chunk to another as Brent guided them to the other side and positioned them for pulling the sled across. Then on cue he launched his team while we lunged against the sled to send it sailing over the bridge. Seeing it veer slightly to the left, Geoff {Carroll} heaved into the side to give it a last split-second correction. The backs of its runners dipped down in the water as it shot up and over a bank of gravelly ice on the far side."

Steger supplies the workaday details of life in a bitterly cold climate that make polar narratives so compelling. They slept fully clothed inside their sleeping bags to be ready in a trice should the ice start cracking beneath them. To satisfy their bodies' cravings for fat, they munched on butter sticks like bananas. In the morning they all left their tents on cue to prevent one group's keeping another waiting and shivering outside. To cope with freezing ink, the journal-keeping Steger would get a relay going between his hand and a supply of thawed pens cached inside his clothing and warmed by his body heat.

He also explains something that may have puzzled many a high-altitude or cold-weather camper: why even people who sleep through the night at home find themselves waking up several times in the tent with full bladders. "Decreasing temperatures trigger a diuretic response," Steger writes, "in which body fluids are voided frequently. It is nature's way of drying out skin and hair in winter, to increase their insulation value when evaporation is minimal."

The expedition differed from the classics in one humane respect. Rather than kill their spent dogs and feed them to the others, Steger and company had them airlifted out -- a feature that also allowed the unforseen evacuation of two injured team members. The planes' arrivals (there were two rendezvous plus a final retrieval of the expeditionary nucleus at the Pole) plunged the expedition into ethical dilemmas. One plane jettisoned two fuel drums. Could the trekkers consider them "just something we found on the ice" and cop any leftover fuel inside them? No, they finally decided.

The group nearly unraveled toward the end, when both food supply and mileage per day were running low. The unveilng of Plan B, by which only Steger and Schurke would make a dash for the Pole, almost caused mutiny. A streak of superb weather vitiated this compromise, and a navigational error fortuitously sent them all sledding around a lengthy open lead. On May 1 1986, five men and one woman (the first to do so) stood on that patch of icefield which, at the time, happened to be covering the geographical concept known as the North Pole.

The expedition's heady pace in the final two weeks lends credence to Peary's candidacy. "{T}he average mileage for our last five marches -- just under thirty-four miles -- was virtually the same as what he clocked on his final dash," Steger writes. "As did we and all other polar expeditions of this century, Peary found steadily improving ice conditions during the last few hundred miles . . ."

Moreover, Steger has studied a photogarph of an island Cook claimed to have sighted a few hundred miles out to sea. Confronted later by the indisputable fact that there is no such island, Cook's supporters called it an icepack that their man had mistaken for land. Steger concludes that the body in the photo is indeed land: "The topography is distinctly geologic, fingerprinting it as a rock formation rather than one of ice." Though Steger does not mention this, Cook was caught passing off a miscaptioned photo on another occassion. Someone exploded his claim to the first ascent of Mt. McKinley by locating the exact spot, on a lesser summit, where he photographed what he said was the top.

Not only did Steger and his band reach the North Pole in roll-out-the-bunting, man (and woman)-against-nature fashion. They also appear to have settled, as certainly as anyone can, the question of who got there first before them.

Dennis Drabelle is a Washington writer and editor; his farthest trip north has been to the north coast of Baffin Island.