From where I sit, I see a lone shepherd on a distant promontory, two trusty dogs at his side, a storm posting with all speed from the cold north as a rogue wolf works the edges of the band. The guard dogs, Great Pyrenees and Akbash, are not quite enough to beat off those wolves, which come night after night in the high country; the shepherd, crook in his hand, his legs stout and hale from a life in the mountains, his eyes sharp at impossible distances, his whole being at one with the forces of the land, is alone, hardened, tough-minded and happy.

I traveled with Peruvian sheepherders working for the Soulen Livestock Company in Idaho during the summers of 2005 and 2006. I went to live out my romantic vision of the shepherd's life, to see wolves, to get a story. The sheep make a seasonal passage from the Snake River Plain in winter up into the mountains north of McCall in the spring and summer. The lambs are born on that range, the ewes live and die out there, and the men too, with their dogs, live out there with eagles and trout and coyotes, year-round.

* * *

That ewe, the dark slick running down her right shoulder? Something is rotting inside the wool, probably a wound from a fall she took, now gone septic.

The sky is brilliant blue, the grasses and pine idling in a mountain wind. Walter Luya comes up behind her, but she stays focused on the grass until her rear foot comes up off the earth in the crook. Walter flips her onto her side. She just lies there, going from terrified to catatonic, waiting to die.

Back home on the Peruvian Altiplano, Walter was a furniture maker and a musician. He played for me the music he recorded with his group, a battered cassette tape squeaking in his old radio. He sends his $750 per month back home to his family: a wife, some children, his aging parents. After six years with the sheep, he's lonely, he tells me, but he can't make a living back home.

Walter exposes a sinister hole in the wool where flies have gotten to the wound and maggots are seething in the flesh. He carves away the rot with his knife. The maggots tumble out onto the sun-hardened ground. It won't take long for the mess to desiccate and blow away.

Now the ewe has a clean wound, and a good bleed. Walter covers it in antiseptic.

"Now, maybe OK," Walter says.

We return to camp to cook supper -- rice with a hash of Spam, carrots, peas, tomato sauce and garlic.

* * *

Guard dogs are wary of people, even the shepherd. But Jethro, a Great Pyrenees, a shaggy god among guard dogs, was oddly tuned. Each time he neared a mountain road, Jethro waited at the edge. A group of friends headed into the mountains would see this massive fur-ball, his jowls hung sentimentally beneath his jaw-line, almost smiling. They'd stop and call to him. He'd wag his tail. Someone would step out of the vehicle, and Jethro would step in. It's almost impossible to get a 120-pound Pyrenees out of a Toyota unless he wants to get out, which he does, but only after he arrives in town.

Soon the party gives up on their mountain journey and returns to McCall, where Jethro jumps out at the small-town animal shelter. There he's got a warm kennel to himself with two easy meals a day. And thus it is that, whenever Jethro goes AWOL, foreman Cesar Ayllon, who after 20 years with the company is an American citizen, heads to the shelter to bail him out.

* * *

On the trail from the lower sagebrush country to the high alpine summer range, we push all day to the summit of Lookout Peak, a snow-topped sentinel over Cascade Lake in June. The trail is hard going, thick black mud into pure deep snow. The sheep stack up against a little deadfall in the trail. God knows why they don't just go around. But the lead ewe stops and then forgets why she stopped, forgets where she was going in the first place, content now to just stand there, nothing at all moving in her smoky brain.

Hector Artica, now in his early 30s, curses and pitches a tree limb to get them moving. It falls flatly on the back of a ewe and she bucks as the group spreads away from her like ripples when a stone goes into a lake. Now the band is streaming out, all the little lambs struck with terror as they lose their mothers in the flow. The lambs are bawling like crazy for their mothers and the mothers are calling back to their lambs: Oh, God, how will we ever find each other again?

Later, the sun down on the horizon, we hump up the last half mile to the mountain bowl where we'll make camp. The ewes spread out to bed down and the lost lambs come looking. I watch it unfold, the little lambs running joyously, bawling and nuzzling at their mother's teats, like families reunited after war.

Kurt Caswell is the author of two books of nonfiction: In the Sun's House: My Year Teaching on the Navajo Reservation, and An Inside Passage, for which he won the 2008 River Teeth Literary Nonfiction Book Prize.