The American Civil Liberties Union and several other immigrants' rights advocates sent a letter to the Department of Homeland Security Thursday condemning "deplorable" conditions inside the Diamondback Correctional Facility in Watonga.
The letter cites widespread reports of medical neglect, insufficient food, severe social deprivation and failure to provide detained people with reasonable access to their legal counsel.
"We have received dozens of harrowing reports about life inside Diamondback," the letter states. "These accounts are strikingly consistent in the concerns they raise."
The 2,160-bed Diamondback Correctional Facility was built in 1998. Before it reopened this year as an immigration detention center, it sat empty for 15 years. In October 2025, the Oklahoma Department of Corrections and the federal government signed a 100 million dollar contract with the private prison company CoreCivic, allowing the company to "hold noncitizens in immigration detention" at Diamondback. Two months later, the facility became operational.
"The uniformity and gravity of these complaints signal to us that ICE and its contractor CoreCivic are operating the facility with blatant disregard for the safety and legal rights of the people in their custody and care," the letter states.
The facility's infrastructure is potentially unfit to facilitate attorney-client visits, according to the letter. The advocates also say immigration detention is civil and not criminal in nature, meaning people at Diamondback are constitutionally entitled to conditions that do not aim to inflict punishment.
"People detained at Diamondback have also alleged that ICE officials systemically deny them reasonable access to counsel and the law library," the letter states. "These barriers to basic legal resources undermine detained people's constitutional rights, depriving them of fundamental fairness in their immigration proceedings."
Travis Handler is a legal fellow for the ACLU of Oklahoma. In a press release, Handler said the Trump Administration's policies have disregarded due process and the rights of those detained.
"We encourage all Oklahomans to hold the Department of Homeland Security and CoreCivic accountable," Handler said in the statement. "Access to necessities like food, medical care, and legal counsel aren't mere suggestions — they are constitutional protected rights to which all detained people are entitled."
The letter details reports of deficient medical treatment. One detained man reported going without his prescription HIV medication for over two weeks, making him more vulnerable to HIV "progressively destroying his immune system." Another woman reported having a urinary tract infection for over a month, despite requests for assistance.
Detained people also reported being deprived of sufficient food and clean drinking water, leading to significant weight loss, according to the letter.
The 14-page letter was signed by people from the ACLU of Oklahoma, the ACLU National Prison Project, Latitude Legal Alliance, YWCA Tulsa, Rivas & Associates law firm, University of Tulsa College of Law Legal Clinic and Council on American-Islamic Relations of Oklahoma.
It was directly addressed to two people at Immigration and Customs Enforcement and the warden at Diamondback Correctional Facility, requesting a meeting with officials to discuss concerns. The Oklahoma Department of Corrections was copied on the letter, along with six federal committees and offices.
"We urge ICE not to process in any new detained noncitizens at Diamondback until it has conducted a comprehensive review and ensures the public that the facility has adequate systems in place to provide for constitutional health care, attorney access, access to outdoor recreation, and processes for swiftly effectuating voluntary departure orders," the letter states.
You can read the full letter here.
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