An empty prison in rural western Oklahoma was an ideal spot to house immigrants as part of the second Trump administration’s ambitious plan to deport millions of people.
U.S. Immigration and Customs Enforcement scrambled to buy warehouses and repurpose military bases and vacant prisons across the country in order to boost its capacity to detain people awaiting deportation proceedings.
The Diamondback Correctional Facility in Watonga once housed prison inmates for the state of Arizona, but had been closed for more than a decade. Its owner, the private prison contractor CoreCivic, now hoped to quickly fill the prison again as part of the growing immigrant detention business. But ICE needed help from the state of Oklahoma to get a deal done quickly.
ICE signed an intragovernmental service agreement with the Oklahoma Department of Corrections for immigration detention at Diamondback in September 2025, a process that several experts told The Frontier can help the federal government bypass competitive bidding and contracting requirements.
The Department of Corrections then outsourced facility operations to CoreCivic, which is projected to earn about $100 million a year from running Diamondback. The Oklahoma Department of Corrections gets almost $10 million a year from the federal government to monitor CoreCivic’s compliance with the state’s agreement with ICE, including federal detention standards, and to “perform other administrative functions.”
Diamondback has rapidly become one of the largest immigration detention centers in the nation since reopening late last year. Data provided by the city of Watonga indicates that Diamondback held an average of 1,923 detainees per day in August.
Complaints of poor conditions at the facility have already emerged. Some detainees have waited days to be entered into the detention center’s online system and assigned a cell, according to interviews with facility employees, two immigration lawyers and a former detainee. In the meantime, they’ve sometimes been confined to holding cells or slept on mats on the floor, unable to contact their families or lawyers.
Sen. Michael Brooks, D-Oklahoma City, who’s also an immigration attorney, said he’s heard concerns from family members of his detained clients that they haven’t been able to access medications for conditions like diabetes during intake.
Elissa Stiles, an immigration attorney based in Tulsa, said one of her clients at Diamondback slept on a mat on the floor for three days and was unable to access medications that she’d received at other facilities while she was waiting for intake. She also said she’s generally unable to get in touch with clients while they’re in intake processing at Diamondback. It can take a few days to a week to receive a call from them, she said.
“I think it’s hard to describe how massive the emotional and psychological impact is on people who are being detained,” Stiles said.
The Department of Corrections has an employee on site at Diamondback who has access “at all times, with or without notice, to detainees, staff and all areas of the facility” and can inspect surveillance video and other records, according to the terms of the state agency’s contract with CoreCivic.
But the Department of Corrections won’t answer basic questions about its responsibilities when monitoring CoreCivic.
At a September Board of Corrections meeting, Justin Farris, executive director of the Department of Corrections, told The Frontier the state agency monitors day-to-day facility operations. When a reporter asked him for more details, he said those standards are available in the agency’s ICE contract. Farris ended the conversation after answering a few questions and walked away.
The agency won’t provide a copy of its full contract with ICE, even though the Oklahoma Attorney General’s office said the document was a public record. The Department of Corrections has not provided a legal reason for withholding it.
A spokeswoman for the Department of Corrections declined to answer questions on conditions at Diamondback and the process it uses to monitor CoreCivic, citing The Frontier’s pending litigation against the state agency. The Frontier and Oklahoma Voice are suing the Department of Corrections to release the full contract with ICE. The Department of Corrections has argued in court that the contract is a federal document and the state agency does not have the authority to release an unredacted copy.
ICE declined to answer questions about the Department of Corrections’ responsibilities under its agreement with CoreCivic. The federal agency said it also monitors conditions on-site at Diamondback for compliance with detention standards.
“ICE’s oversight of Diamondback remains consistent with its oversight responsibilities at other ICE detention facilities,” Sarah Loicano, a spokesperson for ICE, said in an email.
A CoreCivic spokesperson said in an email that the Department of Corrections provides “ongoing oversight” of CoreCivic’s compliance with contractual requirements.
CoreCivic said it operates its facilities in compliance with “all applicable contractual requirements and the standards established by our government partners.”
“The safety, health and well-being of the individuals entrusted to our care at the Diamondback facility are top priorities,” a spokesperson said. “Our responsibility is to care for each person safely, humanely and with dignity while their immigration case proceeds.”

