TOPPENISH, Wash. — By 6 in the morning, Paola Mendoza has pulled her hair back under a baseball cap and donned a long-sleeved sweatshirt to report to her summer job on a farm in Washington's Yakima Valley, known for its apples, pears and hops.

Mendoza is not there to pick fruits or vegetables. She's a research intern working on a project to improve irrigation systems. She spends her days staking the fields and collecting samples alongside her boss, Alan Schreiber, who also employs her mother.

Patricia Mendoza has worked on Schreiber's farm for more than 20 years. She spends her days weeding, thinning, planting and hand-harvesting crops. During peak harvest, she used to work as many as 70 hours a week.

Her earnings have helped provide the family with a decent living. But from the time Paola was young, both her mom and her dad — also a farmworker — were clear about one thing: They did not want her future to be on a farm.

"They were working so hard to provide us with what they didn't have," says Paola, now 20. "They wanted better for me and my siblings."

Her research internship is as close as her parents want her to get to agriculture. In the fall, she'll start her senior year in college, where she's studying to become an elementary school teacher.

Farmers worry about finding enough workers

For farmers across America, finding enough labor has become a top concern. Decades ago, whole families of migrant farmworkers, the majority of them from Mexico, would travel around the U.S., following a route from Texas, through California, and eventually making their way to Washington. Back then, the U.S.-Mexico border was quite porous. Older workers described to NPR crossing through a fence that was no more than chicken wire. Gaping holes were common.

But times have changed. After Sept. 11, 2001, the U.S. stepped up enforcement of the border, and crossing it became a risky endeavor. Farmworkers who were already in the U.S. began to settle. And now, many of them are aging out.

"My workforce is a little like me," says Schreiber. "It's getting a little heavier, and it's getting a little stiffer, and it's starting to have some medical issues."

That's left him worried about where he's going to find enough workers to keep his farm going.

A farmer in Congress raises the alarm

From his farm in the Yakima Valley, Rep. Dan Newhouse, a Republican and third-generation farmer, can see the domestic labor force shrinking.

With farms unable to complete tasks in a timely manner, he says yields may be lower, the quality of the produce may be lower, and farmers will shift away from labor-intensive crops. Already, some farmers in his state have stopped planting asparagus, for instance.

Food is also going to get more expensive, Newhouse warns.

"So it's impacting not just the farmers ... but American consumers as well," he says.

Breaking the cycle of farm work

No single factor has led to the labor shortages farms are experiencing today. But in communities across rural America, a generational shift is contributing.

Consider the life story of Delores Gonzalez, a third-generation farmworker born in Glendale, Ariz. Her childhood is filled with memories of the annual migration from Texas to Washington, working alongside her parents and grandparents from a very young age.

"This was in the 1960s, when we could miss school ... and I could still pick cherries and everything at the age of 9," she says.

Eventually, the family settled in Washington. She married another farmworker and continued to travel to Montana in the summers, bringing her own children to the fields.

Looking back, she says the migrant life instilled in her great morals, values and work ethic, qualities she wanted to pass on to her children. But she also wanted to give them a better life.

"I planted the seed since they were little that they were going to go to college," says Gonzalez.

At 40, when her oldest child was graduating from high school, Gonzalez says something clicked. She wanted something better for herself, too.

"I'm tired of the cycle. I want to break it," she says. Gonzalez and her daughter entered college the same year.

Now, Gonzalez works as a migrant advocate at Grandview High School in the Yakima Valley, helping migrant students and their families get what they need to finish high school.

Jazmin Corona met Gonzalez at the high school four years ago. Corona was 15 at the time and spoke no English. She'd come from Mexico with her father, a farmworker, and joined him in the fields whenever school was out. In the summers, they made the same trek to Montana to pick cherries that Gonzalez had done years before.

Seeing promise, Gonzalez made sure Corona finished high school on time, enrolling her in fast-track summer programs. Corona worked on thick math packets after long days in the fields. As she neared graduation, she recalls her father laying out a choice for her.

"He told me one day, 'I already taught you how to work in the fields outside, under the sun. Now it's your time. You've got to decide if you want to continue here,'" she says.

She thought about how tired her dad has been all these years.

"I want to try something new," she said.

Corona is now 19 and a college student. For the first time in several years, she did not travel to Montana with her dad for the summer cherry harvest. Instead, she returned to the Grandview School District, where she landed a summer job.

"I want to work in the high school, hopefully here in the community," she says. "I feel that I have this connection with people."

Congressman looks to workers from other countries

The farm labor shortage is a concern that has reached the halls of Congress.

The H-2A visa program allows employers to bring in foreign workers for seasonal work, provided they cannot find workers locally to do the job, among other requirements. Use of the program has risen at a fast clip. Washington state alone has seen a nearly 1,700% increase in guest workers over the last 14 years.

But a common complaint is that the program is too expensive and comes with too much red tape.

Newhouse was one of several lawmakers to recently reintroduce a bill, the Farm Workforce Modernization Act, which would cap H-2A wage increases. The bipartisan measure would also allow a limited number of year-round visas for nonseasonal labor, such as picking mushrooms or milking cows.

In addition, the bill would come with some protections for guest workers, including the right for workers to sue their employers. That's something labor advocates have been calling for given the large number and severity of civil rights and wage violations that state and federal investigations have uncovered in recent years.

"I want to make sure that there are fewer obstacles in front of our ability to produce food in this country and to make sure that the American people continue to have an abundant and safe food supply," Newhouse says. "And if we don't have an adequate labor force for the agricultural industry, that's in jeopardy."

Prior versions of the bill failed to gain enough support in Congress. The current version also faces an uphill climb. Moving any immigration-related bill through the Republican-controlled House is difficult.

"But that doesn't mean that the urgency of the problem is any less. In fact, it's greater," says Newhouse.