Thousands of workers at Swift Beef Co., one of the largest meatpacking plants in the United States, will extend their walkout into a third week as they press for higher wages and better health care, union leaders said Friday.

The strike began March 16 at the Swift Beef plant in Greeley, about 50 miles (80 kilometers) northeast of Denver. Union officials said the walkout has the backing of 99% of the plant’s roughly 3,800 workers represented by the United Food and Commercial Workers Local 7, and that thousands have shown up on the picket line during the first two weeks.

Union President Kim Cordova said the company’s proposal falls short, arguing that its offered wage increases do not match inflation. “The workers know the value of their labor,” Cordova said Friday. “This could be a long, drawn out fight.”

With negotiations stalled, JBS USA said it was maintaining operations at limited capacity at the Greeley plant and had shifted beef production elsewhere to meet customer needs. In an email, JBS spokesperson Nikki Richardson said, “We are maintaining supply, supporting the long-term stability of the beef chain, and minimizing disruption for producers, customers, and consumers.” She added that “Our priority is to keep product moving while we work toward a resolution in Greeley.”

Industry experts said it was too early to determine whether the strike would affect retail beef prices, which had already risen to record levels before the walkout. Jennifer Martin, a professor in Colorado State University’s animal sciences department, said the impact could be shaped by how much slaughter capacity exists to absorb disruptions from multiple parts of the industry at once.

Martin noted that changes in slaughter capacity elsewhere have altered the conditions that operators previously faced. She said the industry has become less burdened by excess slaughter capacity that had pressured profit margins, and she pointed to reductions including the closure of a Tyson Foods plant in Nebraska. While she said the lack of harvest capacity at one facility could improve margins across the broader industry, she added that it is “not necessarily in favor of the employees.”

The Greeley strike is the first U.S. slaughterhouse strike since workers walked out at a Hormel plant in Minnesota in 1985, a dispute that lasted more than a year and included violent confrontations between police and protesters. The current contract fight also draws on the plant’s recent history: AP reported that in 2020 the Greeley plant was the site of Colorado’s deadliest workplace coronavirus outbreak, involving 291 infections and six deaths among plant workers.

According to the report, federal regulators later fined JBS $15,615 for failing to protect employees, and during the outbreak President Donald Trump issued an executive order to keep meatpacking plants open amid concerns about the nation’s food supply. In the years after the pandemic, beef companies invested billions to increase slaughter capacity, but Martin said U.S. cattle numbers have since dropped to a 75-year low, in part because of drought and low prices offered to ranchers—meaning additional slaughter capacity may not be as urgently needed.

As the strike continues into its third week, both sides are framing the dispute differently: Cordova has said the company’s offer of 2% wage hikes does not keep pace with inflation and that health care costs absorbed much of the increase, while JBS has said its offer aligns with contract terms reached with UFCW workers at other plants—although it also remains focused on keeping product moving while negotiations proceed in Greeley.