Army Sgt. Georgiana John and Sgt. Ashanti Boatwright dismount while executing a patrol along the protective barrier in Yuma, Ariz., on June 27, 2025. (Erica Esterly/U.S. Army)
AUSTIN, Texas — The military established this week a fourth defense zone along the U.S. border with Mexico — creating a strip of land in Arizona where anyone crossing the border is subject to charges of trespassing on military property as well as border crossing violations.
The Yuma National Defense Area is a 140-mile extension of Marine Corps Air Station Yuma and includes federal property near the Barry M. Goldwater Air Force Range southwest of Phoenix, chief Pentagon spokesman Sean Parnell said Wednesday during a news briefing.
Similar defense areas already exist in Texas and New Mexico and will “continue to enhance the department’s ability to protect the southern border from unlawful entry,” he said.
Creating these military areas allows troops to conduct law enforcement activities just as they would at any other military base, including temporary detention, searches and crowd-control operations.
However, officials with the Joint Task Force Southern Border have said troops continue to allow Customs and Border Protection agents to take the lead as often as possible. Troops have only temporarily detained four of the 450 people detected as trespassing in the roughly two months since patrols began in defense areas in New Mexico and Texas, said Maj. Geoffrey Carmichael, spokesman for the task force, which was established at Fort Huachuca, Ariz., soon after President Donald Trump returned to the White House in late January.
The defense areas are just one part of Trump’s ramped-up border security measures that aim to have no unauthorized crossings across the southern border. Roughly 8,500 troops are deployed under the task force, working primarily to detect possible illegal activity along the border. This includes the use of the Army’s Stryker combat vehicles that have cameras able to observe a two-mile radius.
“We have made incredible progress and will continue to work towards achieving 100% operational control of the border,” Parnell said.
Those troops have conducted about 3,500 patrols, including about 150 in coordination with Customs and Border Protection and Mexican military on the other side of the border, he said.
The New Mexico National Defense Area, established more than two months ago, was the first of these narrow military zones that have been created. It’s roughly 60 feet wide and encompasses about 170 square miles of noncontiguous land. It falls under the Army’s Fort Huachuca.
The El Paso National Defense Area soon followed as part of Fort Bliss in Texas. It includes more than 50 miles of border land from the state’s western edge to the town of Fort Hancock, according to the task force.
Last week, the military confirmed the South Texas National Defense Area as part of Joint Base San Antonio. It was the first such zone to belong to an Air Force installation.
It includes 250 miles of federal property along the Rio Grande, Parnell said.
Detection and monitoring operations have not begun in the two new areas in south Texas and Arizona, Carmichael said.
