SEVERANCE, Colo. — Since he was a boy in western Colorado, John Bartmann seemed destined to become a sheep man. He raised lambs with the local 4-H club and sheared them for elderly German farmers.

His office is lined with paintings of sheep and a plaque honoring him for “promoting culinary excellence” in lambs.

But over the last few years, skyrocketing costs, a brutal drought and plunging lamb prices have battered Bartmann and the 80,000 ranchers across the county who raise sheep — from a few to several thousand.

It is the latest threat to shadow a Western way of life that still relies on the whims of summer rains, lonely immigrant sheep herders and old grazing trails into the mountains.

“For the sheep industry, it’s the perfect storm,” Bartmann said, glancing out his office window here at a bleating sea of wool. “The money is just not there.”

Many ranchers are laying off employees, cutting their flocks and selling at a loss, and industry groups said a handful had abandoned the business entirely. Bartmann has trimmed his flock of 2,000 by one-third.

With prices down more than half since last year and higher costs for gasoline and corn, Bartmann said he expected to lose about $100 for every lamb he sold.

“Even in the good years, you don’t make that much money,” he said. “We can’t take that kind of hit.”

Weather and economics take big shares of the blame. The drought withered grazing grounds, killed off young lambs and dried up irrigation ditches, and a glut of meat and imported lambs from New Zealand helped send prices plummeting.

But some ranchers and officials in Washington, D.C., believe that the deck was stacked against the sheep ranchers by the small and powerful number of feedlots that buy lambs, slaughter them and sell them to grocery stores and restaurants. Even as prices farmers received fell to 85 cents a pound, consumers at supermarkets were paying $7 or more a pound for the same meat.

As cows, pigs, sheep and other animals make their way from the range to kitchen tables, many of them end up in a matrix of feedlots, slaughterhouses and meatpacking facilities where a few companies control a vast share of the market.

The top four companies control about 65 percent of the market for lamb and as much as 85 percent of the market for cows.

That kind of concentration makes it easier for a few powerful companies to manipulate prices to their advantage, said Patrick Woodall, the research director at Food and Water Watch, an environmental-advocacy group.

This fall, several Western senators and ranchers groups wrote to the Agriculture Department saying they suspected that meatpackers had been hoarding sheep in feedlots and keeping prices artificially low. The agency that oversees stockyards said it would investigate.

“We’re going to force a lot of people in the lamb industry out of that business,” said Sen. Jon Tester, D-Mont. “You want competition that’s fair. If you have manipulation, that’s a whole different story.”

In Kaycee, Wyo., Lisa Cunningham said she and other sheep ranchers watched with astonishment as their prices soared and then crashed over the course of the last two years. Cunningham said she was lucky to get $1 a pound for young lambs, down from more than $2.

“You can’t hardly get anyone to buy your lamb,” she said.

Still, even some sheep ranchers do not blame the packers and say they believe that the declines are related to shifts in the market.

Federal insurance has helped blunt the blow, as have government programs to buy lamb from struggling ranchers.

It is the latest twist in a brutal year for thousands of farmers and ranchers across the country. In a slow-motion disaster, a drought covering more than 60 percent of the country scorched corn stalks into brittle parchment, dried up irrigation ponds and turned farm fields into brittle crust.

Farmers begged local governments to let them tap aquifers. Scores of ranchers dumped their livestock at drought auctions.

Farmers say they are still paying near-record prices for corn and hay to feed their livestock through the winter. And if abundant snows do not come to replenish streams and coax new grass from the ground, they worry that next summer could be even worse than last.

“The drought plays into everything,” said Fred Roberts, a sheep rancher in Rock Springs, Wyo. “We have absolutely no feed. We’re feeding as much corn to the sheep as they can eat, and you can imagine how expensive that is. Nothing grew here last year.”

Here in the northern Colorado town of Severance, Bartmann, a man with a Wyatt Earp mustache and a master’s degree in animal production, spends his days managing a lamb feedlot increasingly surrounded by high-end ranch subdivisions.

Even before “the wreck” in prices, he said, his business had been growing increasingly tenuous. A few years ago, he lost big areas of grazing land because it was declared potential habitat for wild bighorn sheep.

The summer drought claimed even more grassland. Now, many of his sheep are spending the winter on a Kansas feedlot. A few hundred others are here, munching hay under gray skies.

Bartmann climbed into a battered pickup to check on them one recent morning, unsure what the next season would bring.

“It just keeps pulling everything down,” he said. “After a while, you say it isn’t worth it.”