A group of nonprofits alleges the federal government illegally transformed more than 100,000 acres of public land along the New Mexico-Mexico border into a military installation so U.S. troops could assist in immigration enforcement.
In a federal lawsuit, the New Mexico Wildlife Federation, Battalion Search and Rescue and Southern Border Communities Coalition argue the Trump administration is misusing so-called “national defense areas” to circumvent longstanding restrictions on military participation in civilian law enforcement.
In a statement, Brian Netter, legal director at Democracy Forward, one of the teams representing the plaintiffs, called the “national defense area” designation “an extraordinary abuse of power with devastating consequences for the people who live, work, worship, recreate, and carry out lifesaving humanitarian work along the border.”
“Public lands do not become military installations simply because the president says so, and the military cannot be handed sweeping new authority to police civilians by drawing a line around land that belonged to the public,” he said, adding, “Our Constitution and laws impose clear limits on the use of the military for civilian law enforcement for a reason.”
The Trump administration began sending troops to the area in March 2025 to support border security and has since expanded the military’s presence along the border in other states. By April of that year, the Defense Department assumed jurisdiction over the 109,651 acres from the Department of the Interior.
The designation made the land, officially named the New Mexico National Defense Area, an expansion of Fort Huachuca for three years. The Defense Department said the designation allowed troops to detain people accused of trespassing in the military area after crossing the border illegally.
However, the lawsuit argues that the federal agencies exceeded their authority to transfer public land through emergency powers. “No statute authorizes the creation of ‘national defense areas,’ let alone permits carving one out of formerly public land,” the lawsuit says.
The lawsuit adds that the Defense Department has historically used such land restrictions only temporarily to protect people or property during accidents or emergencies.
“Creating a semi-permanent military zone along the southern border for purposes of immigration enforcement is directly contrary to the agency’s longstanding practice,” the lawsuit says.
Beyond alleging violations of federal law, the plaintiffs say the military zones are disrupting their work by limiting access to public lands used for recreation and conservation; supporting border communities; and providing humanitarian aid.
James R. Holeman, founder of Battalion Search and Rescue, said his organization leads volunteers who search for people in distress in remote areas and recover the remains of migrants who died crossing the border. Over the past three years, he said, the group’s monthly searches along the Arizona and New Mexico border have uncovered more than 100 death sites.
“Imagine how many more people could be found if we had the access, resources, and support to search systematically. Instead, we’re being locked out,” he said, adding that vast stretches of borderlands are “virtually inaccessible to humanitarian searchers” because of federal designations.
“Now the government is closing off even more territory. We don’t find weapons or drugs. We find Bibles, prayer cards, love notes, and the belongings of people simply trying to survive,” Holeman said. “There is no meaningful, systematic government effort to search for the missing and the dead. They don’t search, and now they’re preventing us from searching.”
