Soldiers conduct a squad patrol along the southern border outside of Sierra Blanca, Texas, on March 31, 2025. (Pfc. Malik Waddy-Fiffee/U.S. Army)
A 60-foot-wide zone of New Mexico land that runs along the U.S. border with Mexico has been deemed part of Fort Huachuca, Ariz., to allow troops to begin arresting people for trespassing on military territory — an escalation of the authority given active-duty service members deployed to the region to deter illegal activity.
Troops can temporarily detain, search, enforce crowd control and provide medical treatment to anyone found on the land referred to as the New Mexico National Defense Area, according to U.S. Northern Command, the combatant command overseeing the deployment of about 6,600 troops at the southwest border.
“Through these enhanced authorities, U.S. Northern Command will ensure those who illegally trespass in the New Mexico National Defense Area are handed over to Customs and Border Protection or our other law enforcement partners,” said Air Force Gen. Gregory Guillot, NORTHCOM commander. “Joint Task Force-Southern Border will conduct enhanced detection and monitoring, which will include vehicle and foot patrols, rotary wing, and fixed surveillance site operations.”
Troops in the area can also request help with temporary barriers, signs and fencing from Fort Huachuca.
The Department of Interior last week transferred the land, known as the Roosevelt Reservation, to the Defense Department as directed by an executive order by President Donald Trump. The Interior Department and Department of Homeland Security were directed to cede jurisdiction to the military.
The noncontiguous land, which is about 170 square miles, runs along the border between New Mexico and Mexico, according to the Army. Under the new arrangement, military personnel will continue to work together with Customs and Border Protection personnel to establish and enforce a controlled perimeter and access to the area to prevent criminal activities across the border.
Border Patrol agents have encountered roughly 30,000 people suspected of crossing into the U.S. without authorization at the southwest border in New Mexico since fiscal 2025 began in October, according to agency data. More than 121,500 people were encountered during the previous fiscal year.
The increase in military authorities at the border with Mexico is building upon an ongoing mission for troops to monitor and report possible criminal activity or people crossing into the U.S. without authorization to Customs and Border Protection. It first began in 2018 during Trump’s first term and continued under former President Joe Biden with the National Guard.
When Trump returned to office in January, he ordered the deployment of active-duty forces. Since then, border crossings have dropped from an average of 5,100 migrants each day under Biden’s four years to 230 a day in the first four months of Trump’s second term, according to Customs and Border Protection.
