A Debut Novel. A Tiny Press. A Pulitzer Finalist.

NEW YORK — Håkan Söderström, the hulking hero of Hernán Diaz’s novel, “In the Distance,” makes a stupendous entrance, ascending onto the first page through a star-shaped void on a featureless plain of white sea ice. Longhaired, white-bearded, gnarled and naked, he pulls himself onto the floe and walks on bow legs to an icebound schooner, carrying a rifle and ax. We are somewhere, nowhere, in the frozen north.

Nowhere is also the place “In the Distance,” Diaz’s first novel, seems to have erupted from. He had no agent when he answered an open call for manuscripts by the nonprofit Coffee House Press in Minneapolis, which published the novel last October. In April, Diaz was named a finalist for the Pulitzer Prize and the PEN/Faulkner Award for Fiction, causing book reviewers around the country to say, Who?

Diaz is a scholar at Columbia University who grew up in Argentina and Sweden, studied in London and New York and lives in Brooklyn. His book is about an immigrant Swede of unusual size journeying in America’s desert frontier between the Gold Rush and the Civil War.

Though many of its elements are familiar to the point of being worn out — saloons and wagon trains, Indians and gold prospectors — the novel is not. Diaz’s long study of North American literature, much of it steeped in the 19th century, allowed him to expertly plunder an antique genre for parts. The rebuilt mechanism is his own design, and it moves in unexpected directions: west to east, around in circles, down into the earth, and north to Alaska.

Which makes “In the Distance” an uncanny achievement: an original Western.

“He’s standing on the shoulders of a lot of giants,” said Chris Fischbach, publisher of Coffee House Press and Diaz’s editor. “It’s a modernist book in that he’s absorbing all these fragments and using those to create a new world, and a new piece of art.”

In a recent interview in a sunny Brooklyn Heights apartment that Diaz shares with his wife, Anne, a filmmaker, and their daughter, Elsa, 7, he talked about the bafflement that led him to Håkan.

He was mystified, he said, by the absence of Western novelists in the American canon. Who, besides Zane Grey and Louis L’Amour and a forgotten brotherhood of pulp novelists? Who, besides Larry McMurtry and Cormac McCarthy? And if those contemporaries write “anti-Westerns,” where are the Westerns they are writing against?

“They’re writing against John Ford, I suppose,” Diaz said.

“It’s weird,” he said. Weird that the Western novel was so underachieving, given how tightly the genre embraces America’s most potent myths about itself. Westerns, he said, glamorize “the worst aspects of the imperial drive of the United States” — brutality against nature, genocidal racism, “the whole macho thing, the place of women, the frivolous violence, it goes on.”

Diaz, it should be clear, is a Western writer who hates guns. He said it sickened him to think that telling Håkan’s story would require imagining and describing acts of murderous violence. “I came very close to not writing the book,” he said. “But I knew something really bad had to happen to him to make the plot plausible.”

Håkan is a backwoods boy from Sweden who leaves home with his older brother, Linus, for the U.S. metropolis they call Nujårk. But he loses Linus on a wharf in Portsmouth, England, boards the wrong ship and ends up in San Francisco. He resolves to reunite with his brother by trudging across the continent, shoes against the current of westward migration and continental conquest.

He knows no English, and for a time the reader is almost as disoriented as Håkan is. Stray words float by in a river of frontier gibberish: “Frawder thur prueless rare shur per thurst. Mirtler freckling thow.” But Håkan learns fast. He meets people: a mystery woman in a corset with amber hair and black-red lips, like a hooker with a heart of coal. A demented gold miner. An obsessive naturalist who wades in alkaline pools for imagined proto-organisms. Homesteaders, marauding Civil War veterans and a sinister sheriff.

Håkan starves and thirsts. He survives and grows, in sorrowful wisdom and, inexplicably, to colossal size. And though he murders and maims and becomes a notorious outlaw, he is disgusted, and ultimately shattered, by his violence.

The reader, absorbed, has urgent questions. Will the misdirected Håkan ford the Mississippi and pass Huck Finn lighting out the other way? Will he find Linus in the sooty hubbub of Walt Whitman’s Brooklyn or the immigrant maelstrom of Five Points? How does he end up in Alaska? More immediately, how do you pronounce Håkan?

Make a fish mouth and glide over the vowels: “Hu-oh-aahk-kan.” To Diaz, it sounds like a Long Islander saying “Hawk can,” which is pretty close for someone whose roots are from nowhere near Massapequa.

He was born in Buenos Aires in 1973. His mother was a psychoanalyst; his father a filmmaker who became involved in Trotskyist politics, which put the family in danger after Argentina’s military coup, when Hernán was 2. They fled to Stockholm. Moving there and then back to Argentina as a boy gave Diaz double doses of immigrant dislocation; the emotional aftereffect of isolation and bullying seem to echo in his story of lonely Håkan.

Unlike his reticent, hulking hero, Diaz has a slight build and a wide smile and an expression that gains intensity as he listens and weighs his words, which he delivers with rapid precision. He is associate director of the Hispanic Institute at Columbia, where he edits the journal Revista Hispánica Moderna, or RHM. His last book was a study of Jorge Luis Borges, the Argentine essayist and poet: “Borges, Between History and Eternity.”

Among the ideas Diaz challenges with “In the Distance” is the one that writing convincingly about a place requires going there at some point.

He didn’t. No rental car and GPS for him: “There was something that to me felt corrupt and dishonest about having an air-conditioned experience of the protagonist’s ordeals,” he said. “I defend the idea of reading over researching, which has this whole protocol that I don’t think applies to literature, which has its own relationship to truth.”

Instead he read widely and deeply and wrote the book in Brooklyn and Manhattan. He knew he was working within an old tradition. Many early Westerns were written by men for whom “Go West” meant crossing the Rhine. They include Karl May, the German scribbler of sauerbraten Westerns, and Franz Kafka (“Amerika”). Arthur Conan Doyle set part of “A Study in Scarlet” in Mormon Utah.

Diaz considered the risks of historical howlers (Kafka imagined the Statue of Liberty holding a sword) and found them tolerable. What he concocted is strange and transporting, a story that approaches but never enters the realm of magical realism. Håkan is one humongous Swede, but not a biblical giant. On a big-enough horse to match his proportions, he can plod down Main Street without causing panic.

Some characters stray toward anachronism, like the opulent winemaker, a sort of Finnish Francis Ford Coppola, who lives on a groomed estate out of Architectural Digest, or Asa, the good guy in a bad gang who loves to cook. Asa is a frontier foodie, adding sweet sap and blossoms to his dishes. He shares with Håkan a few ambiguously tender scenes of manly attachment, and his recipe for quail stew.

Weird. But give Diaz this: It’s a weirdness to which a reader willingly submits because of the vigorous beauty of his words and his ability to keep Håkan’s bizarre adventures somewhere within sight of possibility. So when you get to a sentence like this — “Håkan tried to milk the lion” — it passes without a second thought.

An affecting oddness is the great virtue of “In the Distance,” along with its wrenching evocations of its main character’s loneliness and grief. And its ability to create lustrous mindscapes from wide-open spaces, from voids that are never empty.

“It all could plausibly happen,” Fischbach said. “It probably wouldn’t.”