Darrell Rice stood in a field of corn he’d planted in early June, to be harvested in the fall and chopped up to feed the hundreds of cows and calves he raises in central North Dakota.

“It should be six, seven, eight foot tall,” he said, looking down at the stunted plants at his feet, their normally floppy leaves rolled tight against their stalks to conserve water in the summer heat.

Like ranchers across the state, Mr. Rice is suffering through an epic drought as bad or worse than anywhere else in this season of extreme weather in the Western half of the country.

A lack of snow last winter and almost no spring rain have created the driest conditions in generations. Ranchers are being forced to sell off portions of herds they have built up for years, often at fire-sale prices, to stay in business.

Some won’t make it.

“It’s a really bad situation,” said Randy Weigel, a cattle buyer, who said this drought may force some older ranchers to retire. “They’ve worked all their lives to get their cow herd to where they want, and now they don’t have enough feed to feed them.”

Since December, in the weekly maps produced by the United States Drought Monitor, all of North Dakota has been colored in shades of yellow, orange and red, symbolizing various degrees of drought. And since mid-May, McHenry County, where Mr. Rice ranches and farms, has been squarely in the middle of a swath of the darkest red, denoting the most extreme conditions.

The period from January 2020 to this June has been the driest 18 months in McHenry and 11 other counties in the state since modern record keeping began 126 years ago, according to the National Oceanic and Atmospheric Administration.

“I’ve been ranching for 47 years and then this year had to come along,” said John Marshall, who ranches with his son, Lane, not far from Mr. Rice in this sprawling county where the county seat, Towner, bills itself as the cattle capital of North Dakota. “It’s the worst thing I can ever remember.”

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Drought conditions that are affecting nearly half the land area of the lower 48 states are helping send beef prices higher in America’s grocery stores. But ranchers here say they aren’t seeing that money — slaughterhouses and other middlemen are. If anything, the ranchers said, they are losing money because they are getting less from the forced sale of their animals.

The Marshalls have already sold about 100 cows and plan to sell at least another 120, which would leave them with about two-thirds of their usual herd. “Never had to do it before,” Mr. Marshall said.

Mr. Rice’s corn, which is stored as silage to feed his animals later in the year, is so short that if he tried to harvest now it he couldn’t. “It’s unchoppable,” he said.

If he gets some rain — a big if, as the forecast into the fall is for continued heat and dryness — the corn may reach six feet, or half its usual height. Even then he would be looking at a shortage of feed, and would very likely have to have his cows weighed at the communal ranchers’ scale off Main Street in Towner and then sold to a buyer elsewhere.

“If we don’t get silage,” he said, “the cows are going to town.”

Rachel Wald, who works for North Dakota State University advising and supporting ranchers, said that livestock auction houses, called sale barns, had been very busy this spring and summer. “We’ve got 2,000 critters heading down the road each week” in the county, she said. By some estimates, half the cattle in the state may be gone by fall.

For ranchers who have spent years building up the genetics of their herd, that can mean a giant step backward. “Every year we try to better our breed,” said Shelby Wallman, who with her husband, Daryl, has been ranching for decades in Rhame, in the southwestern corner of the state.

“It’s a calling,” she said. “You spend your entire life with these cattle. I can tell you, there’s going to be tears.”

North Dakotans have seen drought many times before. One in 1988 was particularly bad, although John Marshall and others who made it through that year said the current drought is worse.

Ranchers point to the variable nature of the climate here — where a dry year or two may easily be followed by a wet period — instead of talking about climate change. Yet climate change is occurring in North Dakota, as it is everywhere else.