Dennis Drabelle is a former contributing editor of Book World.

The two sides of Bryce Andrews — enlightened rancher and sensitive writer — appear to make a smooth fit. The grizzly bears of western Montana that he writes about, however, mean only one thing to most of the region’s farmers: a threat to their corn crops. The tensions between these animal opportunists and the humans whose livelihoods they interfere with lie at the heart of “Down From the Mountain,” Andrews’s poignant and disturbing new book.

Andrews came to Montana after growing up in Seattle and graduating from Whitman College in Walla Walla, Wash. After working as a ranch hand for a decade, he took a job with People and Carnivores, a small conservation group in Bozeman, Mont. His first big assignment is to extend the group’s reach to a new area, Mission Valley. It’s here that Andrews encounters Millie, the name of both the grizzly sow whose life and death he chronicles and of the woodlands where the animal lives. (Both give homage to a local farmer who managed to coexist uneventfully with bears for seven decades. )

Andrews discovers that all sorts of people share this part of the world with the carnivores he hopes to save. It lies within the Flathead Indian Reservation, which is home to members of at least three tribes. The reservation is also honeycombed with non-tribal tracts thanks to a 19th-century law that encouraged Native Americans to become individual land owners, free to sell to anyone. The reservation has its own complement of natural-resource specialists, who appear to do fine work, although their job is made harder by having so many non-Native property owners to deal with.

Andrews works out a modus vivendi with one such non-Native, Greg Schock, a dairy farmer who also raises corn, some of which he is losing to grizzlies. Schock is a good guy. He wants to maintain a live-and-let-live policy toward the bears, but he can’t afford to pay for the electric fence that might keep them out of his cornfield. Andrews obliges by figuring out ways to cut costs and volunteering to build the fence himself. At stake for Millie and other bears in the vicinity is nothing less than life itself. As Andrews notes, “When grizzlies could not be broken of their bad habits and continually ended up in trouble, [the Flathead wildlife experts] were responsible for killing them.”

The fence works pretty well, and Andrews is busy improving it when a grim discovery comes to light. Millie, who has two female cubs, has been shot: “Lead pellets struck her head-on, shattering the bridge of her nose and burying themselves in the skin around her eyes. In their wake came darkness and scalding pain. Tasting blood and seeing almost nothing, she ran blindly with the cubs at her heels.”

Saving Millie, it soon becomes clear, is not possible. Her wounds will suppurate and be infected until she is in ceaseless pain and unable to spare a thought for her cubs; she has to be put down. The remainder of the book follows two efforts: to place Millie’s cubs in a zoo or comparable facility because, without their mother to teach them, they will never learn to live in the wild; and to identify the shooter (since grizzlies are a protected species, whoever wounded Millie committed a crime unless it was a case of self-defense).

A leitmotif in “Down From the Mountain” is the disruption caused by climate change. An elderly rancher tells Andrews that spring now comes a month earlier than it did when he was young. And whitebark pine nuts, an oil-rich component of grizzlies’ diet, are scarce these days. Beetles that eat pine bark used to be held in check by early hard freezes, which killed larvae before they could produce the internal antifreeze that gets them through the winter. With hard freezes becoming increasingly rare, more larvae are growing into adult beetles that systematically eat bark, girdling and killing the trees, “turning whole slopes from green to red.”

Andrews writes precise and evocative prose. Setting the scene early in the book, he compares certain parts of “Montana’s western rampart” to coastal Washington state. “This lush, plentiful inflection is nowhere stronger than in the Mission Valley, where cattails choke the sloughs and fruit trees sprout unbidden. In the mountains grow healthy, if isolated, groves of red cedar. Bracken ferns sprout in the shelter of their boughs, rising plumelike from the duff.” Later, while viewing footage from a trail camera that shows what the doomed Millie looks like after being shot, he laments “the ruined geometry of her face.”

At times Andrews admits to being discouraged. “If one person in a hundred leaves corn, chicken coops, or garbage cans unprotected, then takes a potshot at a sow come looking for a meal,” he writes, “it will be enough to damn the grizzlies persisting in Montana.” But the book ends with him and his fiancee buying a farm in the region, which they will take care of secure in the knowledge that, thanks to the conservation easement they’ve attached to the land, no future owner will be able to subdivide it. Meanwhile, the electric fence they will put up should be a model of bear-excluding ingenuity.

Down from
the Mountain

The Life and Death of a Grizzly Bear

By Bryce Andrews

Houghton Mifflin Harcourt.
288 pp. $25