A flavorful trek across Alaska; Going to Extremes, By Joe McGinniss. New York: Alfred A. Knopf. $11.95.

Deep in the heart of Joe McGinniss's new book about Alaska, a character named Ray Bane surveys the summer splendor and observes, "All this is a lie. A beautiful lie. Winter is the truth about Alaska."

McGinniss may have found his thesis in that quote. Although obviously enamored with all his real-life characters, he sees through Alaska's beautiful lie. In the wintry soul of contradiction and confusion, he lands squarely on the truth.

"Going the Extremes," is a title that applies as aptly to his work as to the Alaskans he so ably pictures. This is no gambol through woodlands of "America's last great wilderness"; it's a journey across a human landscape as remote from average America as the surface of the moon.

The people he encounters, some of them rough and outspoken, all seem to share the experience he ascribes to the continent's most northern city of Barrow -- "life in the caboose of the world." With obvious affectation, he catalogs the counterpoints of Alaskan life: a young couple whose cabin attracts friends and threatens the wilderness they love, for instance; or the pilgrim who trades a fresh start in Alaska for a suite in a corporate tower.

Inevitable comparison with John McPhee's 1977 best-selling "Coming Into the Country" leaves the reader with a striking conclusion: The two books work in unplanned tandem, ranging across the vastness of Alaska like a latter-day Lewis and Clark to explore the wilderness of both tundra and imagination.

By background and inclination, each author seems to have concentrated on his area of greatest strength: McPhee at play in the natural wonders of the state, McGinniss searching through the personalities, sometimes raw, that people the frontier. There is no firm line of demarcation, of course. Each has wandered through both meadows and barrooms, and each accurately reflects the fact that it's impossible to separate Alaskans from their land; you can't understand one without the other.

Indeed, the longest section in the McGinniss work is an ode to Alaska's outdoors, the story of a Brooks Range expedition alive with grand description and the awe of a city boy gone country. But even in the wilds, McGinniss's unique perspective is evident: "At first [the valley] appeared to be covered with fog, but as we drew steadily closer we observed that it was not fog at all, but one long, thin cloud that was being blown back and forth, up and down the valley, by shifting winds. 'That cloud is flowing though the valley like a river,' Ray Bane said, which indicated how different his orientation was from my own. To me the cloud had seemed like a subway: shuttling between grand Central Station and Times Square."

If there had been a subway in Alaska, Joe McGinniss would have ridden it. He seems to have done almost everything else. He lived in Alaska through much of 1975 and 1976, years of pipeline boom and brawl that he has captured in the 18 distinct sections of this remarkable book. McGinniss discovered the wages of greed in the person of a used-up Valdez prostitute turned cocaine courier -- and found God's handiwork stunningly displayed in a remote mountain meadow that had probably never been seen by man before.

The book is first-person reporting at its finest -- honest and perceptive, written in clean, simple prose that rings with autenticity.

Like the election that catapulted him to national attention with "The Selling of the President, 1968," Alaska proved a subject worthy of the reporting skills so evident in "Going to Extremes." The rewarding, impressive portrait should earn McGinniss a position in the front rank of American reporters.