Oliver, as a Times profile a few years ago put it, likes to present herself as “the kind of old-fashioned poet who walks the woods most days, accompanied by dog and notepad.” (The occasion for the profile was the release of a book of Oliver’s poems about dogs, which, naturally, endeared her further to her loyal readers while generating a new round of guffaws from her critics.) She picked up the habit as a child in Maple Heights, Ohio, where she was born, in 1935. Walking the woods, with Whitman in her knapsack, was her escape from an unhappy home life: a sexually abusive father, a neglectful mother. “It was a very dark and broken house that I came from,” she told Tippett. “To this day, I don’t care for the enclosure of buildings.” She began writing poetry at the age of thirteen. “I made a world out of words,” she told Shriver in the interview in O. “And it was my salvation.”

It was in childhood as well that Oliver discovered both her belief in God and her skepticism about organized religion. In Sunday school, she told Tippett, “I had trouble with the Resurrection. . . . But I was still probably more interested than many of the kids who did enter into the church.” Nature, however, with its endless cycles of death and rebirth, fascinated her. Walking in the woods, she developed a method that has become the hallmark of her poetry, taking notice simply of whatever happens to present itself. Like Rumi, another of her models, Oliver seeks to combine the spiritual life with the concrete: an encounter with a deer, the kisses of a lover, even a deformed and stillborn kitten. “To pay attention, this is our endless and proper work,” she writes.

In 1953, the day after she graduated from high school, Oliver left home. On a whim, she decided to drive to Austerlitz, in upstate New York, to visit Steepletop, the estate of the late poet Edna St. Vincent Millay. She and Millay’s sister Norma became friends, and Oliver “more or less lived there for the next six or seven years,” helping organize Millay’s papers. She took classes at Ohio State University and at Vassar, though without earning a degree, and eventually moved to New York City.

On a return visit to Austerlitz, in the late fifties, Oliver met the photographer Molly Malone Cook, ten years her senior. “I took one look and fell, hook and tumble,” she would later write. “M. took one look at me, and put on her dark glasses, along with an obvious dose of reserve.” Cook lived near Oliver in the East Village, where they began to see each other “little by little.” In 1964, Oliver joined Cook in Provincetown, Massachusetts, where Cook for several years operated a photography studio and ran a bookshop. (Among her employees was the filmmaker John Waters, who later remembered Cook as “a wonderfully gruff woman who allowed her help to be rude to obnoxious tourist customers.”) The two women remained together until Cook’s death, in 2005, at the age of eighty. All Oliver’s books, to that date, are dedicated to Cook.

During Oliver’s forty-plus years in Provincetown—she now lives in Florida, where, she says, “I’m trying very hard to love the mangroves”—she seems to have been regarded as a cross between a celebrity recluse and a village oracle. “I very much wished not to be noticed, and to be left alone, and I sort of succeeded,” she has said. She tells of being greeted regularly at the hardware store by the local plumber; he would ask how her work was going, and she his: “There was no sense of éliteness or difference.” On the morning the Pulitzer was announced, she was scouring the town dump for shingles to use on her house. A friend who had heard the news noticed her there and joked, “Looking for your old manuscripts?”

Oliver’s work hews so closely to the local landmarks—Blackwater Pond, Herring Cove Beach—that a travel writer at the Times once put together a self-guided tour of Provincetown using only Oliver’s poetry. She did occasional stints of teaching elsewhere, but for the most part stayed unusually rooted to her home base. “People say to me: wouldn’t you like to see Yosemite? The Bay of Fundy? The Brooks Range?” she wrote, in her essay collection “Long Life.” “I smile and answer, ‘Oh yes—sometime,’ and go off to my woods, my ponds, my sun-filled harbor, no more than a blue comma on the map of the world but, to me, the emblem of everything.” Like Joseph Mitchell, she collects botanical names: mullein, buckthorn, everlasting. Early poems often depict her foraging for food, gathering mussels, clams, mushrooms, or berries. It’s not an affectation—she and Cook, especially when they were starting out and quite poor, were known to feed themselves this way.

But the lives of animals—giving birth, hunting for food, dying—are Oliver’s primary focus. In comparison, the human is self-conscious, cerebral, imperfect. “There is only one question; / how to love this world,” Oliver writes, in “Spring,” a poem about a black bear, which concludes, “all day I think of her— / her white teeth, / her wordlessness, / her perfect love.” The child who had trouble with the concept of Resurrection in church finds it more easily in the wild. “These are the woods you love, / where the secret name / of every death is life again,” she writes, in “Skunk Cabbage.” Rebirth, for Oliver, is not merely spiritual but often intensely physical. The speaker in the early poem “The Rabbit” describes how bad weather prevents her from acting on her desire to bury a dead rabbit she’s seen outside. Later, she discovers “a small bird’s nest lined pale / and silvery and the chicks— / are you listening, death?—warm in the rabbit’s fur.” There are shades of E. E. Cummings, Oliver’s onetime neighbor in Manhattan, in that interjection.

Oliver can be an enticing celebrant of pure pleasure—in one poem she imagines herself, with a touch of eroticism, as a bear foraging for blackberries—but more often there is a moral to her poems. It tends to be an answer, or an attempt at an answer, to the question that seems to drive just about all Oliver’s work: How are we to live? “Wild Geese” opens with these lines:

You do not have to be good.
You do not have to walk on your knees
for a hundred miles through the desert repenting.
You only have to let the soft animal of your body
love what it loves.
Tell me about despair, yours, and I will tell you mine.

The speaker’s consolation comes from the knowledge that the world goes on, that one’s despair is only the smallest part of it—“May I be the tiniest nail in the house of the universe, tiny but useful,” Oliver writes elsewhere—and that everything must eventually find its proper place:

Whoever you are, no matter how lonely,
the world offers itself to your imagination,
calls to you like the wild geese, harsh and exciting—
over and over announcing your place
in the family of things.

In addition to Rumi, Oliver’s spiritual model for some of these poems might be Rainer Maria Rilke’s “Archaic Torso of Apollo,” a frequent reference point. Rilke’s poem, a tightly constructed sonnet, depicts the speaker confronting a broken statue of the god and ends with the abrupt exhortation “You must change your life.” Oliver’s “Swan,” a poem composed entirely in questions, presents an encounter with a swan rather than with a work of art, but to her the bird is similarly powerful. “And have you too finally figured out what beauty is for? / And have you changed your life?” the poem concludes. Similarly, “Invitation” asks the reader to linger and watch goldfinches engaged in a “rather ridiculous performance”:

It could mean something.
It could mean everything.
It could be what Rilke meant, when he wrote,
You must change your life.

Is it, in fact, what Rilke meant? His poem treats an encounter with a work of art that is also, somehow, an encounter with a god—a headless figure that nonetheless seems to see him and challenge him. We don’t know why it calls on him to change his life; or, if he chooses to heed its call, how he will transform; or what it is about the speaker’s life that now seems inadequate in the face of art, in the face of the god. The words come like a thunderbolt at the end of the poem, without preparation or warning.

In keeping with the American impulse toward self-improvement, the transformation Oliver seeks is both simpler and more explicit. Unlike Rilke, she offers a blueprint for how to go about it. Just pay attention, she says, to the natural world around you—the goldfinches, the swan, the wild geese. They will tell you what you need to know. With a few exceptions, Oliver’s poems don’t end in thunderbolts. Theirs is a gentler form of moral direction.