The cows amble toward the milking parlor with a languid ease that brings a smile to Magdaleno Tecpile’s face. Such divas, those ladies. He whistles softly at the laggards, nodding toward the open gate at the front of the pen, before returning to the task of scraping their droppings from the barn floor. “They will go by themselves,” he says in Spanish. “They know when it’s time to be milked.”

In the daily rhythm of a modern dairy, routine breeds familiarity. It’s true for the cows, and so it is for Tecpile (pronounced Tec-PEE-lay), a dark-eyed young man whose face holds a strong memory of boyhood. Two years ago, living with his family in a village in rural eastern Mexico, he had never touched a dairy cow. Now he milks several hundred during a single 10-hour shift in the barn. For six days a week and 312 days a year—no holidays on a dairy farm—he ensures the uninterrupted flow of milk on the farm, one of the largest in Wisconsin’s Buffalo County. Without employees like him, owner John Rosenow says simply, “I would be in serious trouble.”

Rosenow is not alone. From Manitowoc to the Mississippi River, Wisconsin’s signature agricultural industry increasingly depends on people such as Tecpile—immigrants, chiefly from Mexico and Latin America, who followed the path of economic opportunity thousands of miles to the American heartland. According to a new study led by CALS rural sociologist Jill Harrison, at least 5,300 foreign-born laborers now work on Wisconsin dairy farms, representing more than 40 percent of the farms’ hired labor. On dairies with 1,200 cows or more, seven in 10 workers are immigrants, working an average of 57 hours a week.

Those figures describe a fast-moving trend that has fundamentally changed the face of Wisconsin dairy in the past decade. But they also hint at issues that deeply divide the American political landscape. It is likely, for example, that a significant number of these new immigrants lack legal authorization to work in the United States. Although Harrison’s study didn’t ask about documentation—mostly because the answers workers offer to survey takers on the issue are predictably unreliable—other estimates say 40 to 70 percent of immigrants working in U.S. agricultural jobs are undocumented. Similar findings have been made in surveys of construction and hospitality workers, two other occupations that have become significantly populated by immigrants. Depending on whom you ask, the reliance of these industries on illegal workers is either an economic necessity or an intolerable flaunting of the law. Either way, it raises hard questions about national immigration policy, a debate that swirls in deeply held passions about economics, race and justice.

But in Buffalo County, those tensions play out on a smaller stage, in the daily thrum and churn of dairies like Rosenow’s, where the milking never stops in a parlor filled by the sounds of salsa music. “This is probably the biggest change to come to this community in 150 years,” says Carl Duley, UW-Extension’s agricultural agent for the county. And with change comes challenge … and opportunity.

Shouldered against an eastward jog of the Mississippi River an hour north of La Crosse, Buffalo County is archetypical Wisconsin dairy country, where cows outnumber people by nearly five to one. Some 200 dairy farms dot its 712 square miles, a rolling terrain of verdant valleys and towering bluffs that climb like stairs from the river basin. When German and Norwegian immigrants arrived here in the 1850s, they planted those valleys with wheat, but battling insects and the sloping terrain proved too much. Buffalo County has tied its fortunes to animals ever since.

Among those early immigrants were John Rosenow’s great-grandparents, Swiss and German homesteaders who settled on an emerald sward of pasture a few miles east of Alma, the county seat. By the time Rosenow inherited the farm in 1972, it was already among the county’s largest, milking a herd of 100 Holsteins. Through modernization and mergers with neighboring farms, Rosenow has grown the operation to 550 cows, which mill about under an enormous free-stall barn.

As the farm grew, its unrelenting demands took a toll on Rosenow and his business partners. “We were really working our tails off, putting in 90 and 95 hours a week regularly. And we still weren’t getting things done the way we wanted,” he says. Hired help came and went, and after a while, it didn’t come at all. With the roaring 1990s economy pushing unemployment to historic lows, the labor pool in rural America all but dried out. “Everyone who hired employees outside the family was struggling to fill positions,” recalls Carl Duley. “There was just no labor.”

Crop farmers filled the gaps with students and foreign workers, who can be hired legally under temporary seasonal work permits. But those programs offered little help for dairy, where the need for labor is year-round. Rosenow tried to make do with the peripheral characters who showed up seeking jobs, men who often sunk into drug or alcohol addiction and mishandled the cows. But by 1998, he was desperate enough to try a last resort. He flipped to the back of his Hoard’s Dairyman and found an ad for a Texas agency called Amigos, which offered assistance in finding Mexican workers for dairy farms. He wrote a check for $375, and a short time later, he drove to the bus station to pick up a man named Manuel. Not knowing a word of Spanish, Rosenow sat Manuel in his milking parlor and demonstrated the equipment. “He started work the next day, and he worked the next 54 days straight,” recalls Rosenow. By the end of the year, he had hired two more workers through Amigos. Now, nine of his 20 employees are Mexican.

Rosenow admits that he was at first daunted by hiring foreign-born workers. He fretted about communicating with employees who spoke no English. Having never known anyone from Mexico, his assumptions were framed by the stereotypes he saw in movies. But his illusions evaporated when he saw the results in the barn. “They’re very gentle with the cows,” he says, noting that the amount of milk the dairy loses due to mastitis is one-third the state average. “They’re reliable and consistent, and they want to work hard.”

Rosenow is not blind to the circumstances that drive that reliability. For men like Magdaleno Tecpile, farm labor offers an escape from devastating poverty at home, where jobs, if they can be found at all, often pay less than $10 a day. On Rosenow’s farm Tecpile makes more than nine times that, sending a significant share back to Mexico to support his extended family, including a wife and an eight-year-old son he hasn’t seen in two years. He wants little more than to earn enough money to give his family a better life.

But in truth, there are few other options. Dairy hours are too long and physically taxing to allow for much socializing. Driving is risky, as most immigrant workers lack U.S. licenses. Instead, the men on Rosenow’s farm unwind in the apartments that he provides for them, traveling into town for groceries and the occasional stop at the post office. Tecpile spends much of his free time in Rosenow’s workshop, where he is learning woodworking in hopes of opening a furniture shop in Mexico. Asked if he ever gets bored, he shakes his head no. “For now, this is the option I have, and I like it,” he says through a translator. “But if we had to leave or couldn’t work here any more, I would do any job, as long as I can work.”

This sense of social invisibility echoes through Jill Harrison’s research, which paints an intimate portrait of the dynamics of the new wave of immigration. In 2008, Harrison and her graduate students fanned out over 83 dairy farms to ask owners and workers about their jobs, from the mundane minutiae of wages and benefits to more searching questions about their hopes and ambitions. What they heard were the tales of people who live in the shadows of a society that rarely acknowledges their presence. Workers spoke of pride in their jobs and their desire to learn new skills, but they also related fears about living outside the system—fears that often kept them from branching out into their communities. Although nearly all of the workers in Harrison’s survey said they wanted to learn more English, for example, very few said taking classes was a viable option. “They don’t want to make themselves visible any more than necessary,” says Harrison.

A native Californian with a Ph.D. in environmental studies, Harrison knew little about Wisconsin dairy when she was hired by the university in 2006. But her doctoral thesis, a study of California’s lax regulations on pesticide application, gave her a taste of the uneven terrain of farm labor relations. Her research concluded that power inequities kept immigrant workers from reporting medical problems related to pesticide exposure, potentially obscuring the true depth of the harm.

When she began studying Wisconsin farms, she saw similarities, but also some notable differences. While California leans on seasonal workers to harvest fruits and vegetables, for instance, dairy’s year-round work makes Wisconsin’s immigrant laborers somewhat more firmly rooted. The average worker in Harrison’s surveys had been at the same job for nearly three years. Twenty percent of the workers are women, and a growing number live with spouses and children. In many ways, they resemble the European immigrants who settled Wisconsin in the 1800s, she says.

But Harrison cautions against reading those data as signs of absolute stability. “There are different dynamics in place now that create significant vulnerabilities for both employers and for employees,” she says.

The most significant risk comes from the shifting winds of U.S. immigration policy and enforcement. When Wisconsin dairy farmers began hiring foreign workers in the 1990s, the U.S. government generally regarded the possibility that those workers lacked proper documentation with a winking nonchalance. The 2001 terrorist attacks brought on a harder attitude, and border security and law enforcement have intensified significantly. Farmers are especially worried about the aggressive tactics of the Department of Homeland Security’s Immigration and Customs Enforcement division, which has raided dozens of farms and factories suspected of employing illegal immigrants. In 2008, ICE raids led to the deportation of more than 6,000 immigrants, a fact that terrifies farmers such as Rosenow. “Of all the worries we have to deal with on this farm, that’s the biggest. It’s whether ICE will come knocking,” he says.

Many dairy farmers have stepped up efforts to change the system. Rosenow serves on a governor’s committee that has proposed driver’s certificates and other social services for foreign workers. Nationally, industry groups are pushing a bill currently before the U.S. House of Representatives that would extend the term of seasonal H2A work permits to three years for dairy and sheep workers.

Laurie Fischer, executive director of the 750-member Wisconsin Dairy Business Association, says the changes are necessary to address the shifts in the labor market that began in the 1990s. “The workforce in the United States is in decline, and we can expect this trend to continue,” she says. “Even during times of high unemployment, our members find that few native-born employees are interested in working on dairy farms and very few apply.”

But the opposition to such measures is well organized. Groups such as NumbersUSA, a policy organization that says it represents more than 1 million members, claim that such reforms create amnesty for illegal immigrants and rob Americans of job opportunities. Heated arguments over amnesty helped kill a 2007 bill that would have expanded and enhanced guest worker programs. And while many farmers are encouraged by President Obama’s recent rhetoric on immigration, the reform package remains stalled in a congressional committee.

To Rosenow, the inertia reveals something dark about Americans’ complacency on the issue. “We want these people to do the jobs that they’re doing, but we don’t want to see them,” he says. “We want them to pick our strawberries and our apples, but we don’t want them to have any rights. We don’t want to learn their culture, and we don’t want to change ours. It doesn’t make any sense.”

Except that it might make perfect sense. As Harrison points out, keeping foreign workers in legal limbo creates a powerful incentive for workers to accept whatever conditions they are offered.

“You hear people say that these workers are gaming the system (by not coming here legally), and in some ways they are. But I don’t think that’s the real story,” she says. “Really, the system is gaming them. We benefit tremendously from their labor, and it’s high time we recognize that. It’s time to bring them out of the shadows.”

The thing about shadows, though, is that they can be a safe place to hide. And for ethnic and cultural minorities, the light is not always kind.

Just east of Buffalo County, Trempealeau County’s Latino population has grown by a staggering 940 percent since 1990, one of the most profound demographic makeovers in the country. Previously homogenous towns such as Arcadia, where two large factories employ many Latino workers, have become suddenly cosmopolitan, and the transition has not always been easy. In 2006, Arcadia mayor John Kimmel made a hamfisted attempt to appease concerns about illegal immigration by proposing a passel of anti-immigrant ordinances, including a mandate that town business be conducted only in English and a curious ban on flying flags of other countries unless they were accompanied by an American flag. The ordinances failed, and Kimmel later apologized.

Buffalo County has not experienced such incidents, but the relative harmony may be deceiving. According to the Pew Hispanic Center, just 132 of the county’s 13,812 residents in 2007 were Latino. Many of those live on dairy farms, isolated from the kind of cultural interchange that can lead to conflict.

“We’re still in that awkward place right now, where there’s not a lot of real connection,” says Shaun Duvall, a former Alma high school Spanish teacher who runs Puentes/Bridges, an organization that fosters cultural exchange among farmers and Latino workers. As the name suggests, Puentes is about building bridges, using both language instruction and cultural immersion to help farmers and workers find common ground. Duvall visits 40 farms each month to translate and teach language classes, and she leads annual trips to Mexico to introduce farmers to the culture and economic conditions of their employees’ homeland.

“The whole point is understanding,” she says. “If we just try to make them be like us, what have we gained? We haven’t learned anything.”

And around Alma, there are signs of cultural integration, such as the one posted on the window of the town’s one-room public library: “Hablamos Español … un poquito.” Inside, librarian Marie Marquardt shows off a shelf of recently acquired Spanish instruction guides, which sit next to a new computer purchased with grant money. Last fall, Marquardt and Duvall organized a Spanish language primer that was attended by 17 local business owners. They hope to repeat the course again this year.

But no one in Buffalo County expects the learning to be fast and easy. At a coffee shop overlooking the barges that steam down the Mississippi, Carl Duley relates a story about an unincorporated town just up the highway, where a German Lutheran church still stands across the street from a Norwegian Lutheran church. “It wasn’t until pretty recently—maybe the last generation—that those two churches talked to each other. One service was in German and one was in Norwegian, and that lasted for about 50 years,” he says. “So this is nothing new. But we hope we can do some things to make it go a little faster this time.”