Thousands of farmworkers are prioritized for vaccinations.

The desert valley tucked behind the San Jacinto Mountains in California is best known for the Coachella music festival and a series of lush resort towns where well-heeled snowbirds go to golf, sunbathe and party.

But just beyond the turquoise swimming pools of Palm Springs, more than 10,000 farmworkers harvest some of the country’s largest crops of date palms, vegetables and fruits.

Mainly undocumented immigrants, they have borne the brunt of the pandemic in California: In some areas, up to 40 percent of the workers tested for the virus had positive results. The Rev. Francisco Gómez at Our Lady of Soledad church in Coachella said his parish had been averaging 10 burials a week. “You’re talking about an apocalyptic situation,” he said.

Ending the virus’s rampage through farm country has been one of the United States’ biggest challenges. Undocumented immigrants are wary of registering for government programs or flocking to public vaccination sites, and the idea of offering the shots to immigrants who are in the country illegally ahead of other Americans has spurred debate, particularly among some Republican members of Congress.

But a landmark effort is underway across the Coachella Valley to bring the vaccines directly into the fields. Thousands of farm workers are being pulled into pop-up vaccination clinics hosted by growers and run by the Health Department.

The county is the first in the nation to prioritize farm workers for vaccination, regardless of their age and health conditions, on a large scale. But epidemiologists say such programs will need to expand significantly to have any chance of ending one of the biggest threats to the stability of the country’s food supply.

Hundreds of outbreaks have crippled the work force on farms and in food processing centers across the country. Researchers from Purdue University in Indiana estimate that about 500,000 agricultural workers have tested positive and at least 9,000 have died.

The challenges to getting farmworkers vaccinated go well beyond worries about their immigration status. The odds of being able to sign up for a vaccine online are low in a population that often lacks broadband access and faces language barriers. Many cannot easily reach vaccination sites in urban areas because they do not have reliable transportation or the ability to leave work in the middle of the day.