By Bethany Blankley
The Center Square

The Trump administration is cracking down on Mexican cartel-dug tunnels at the southwest border. The tunnels are built and used to smuggle drugs, weapons, people and other illicit contraband, authorities have found.

Two major finds this year were in the high traffic areas of El Paso, Texas, and San Diego, California, where established cartel operations have controlled the areas for years.

In addition to ongoing border security efforts, the Trump administration is expanding its Persistent Surveillance and Detection System (PDS) to strengthen tunnel detection capabilities along high-risk areas of the southwest border. The PDS is managed by U.S. Customs and Border Protection and Border Patrol.

On Monday, the Department of Homeland Security released a solicitation for a $100 million contract to expand the PDS as part of its Cross Border Tunnel Threat (CBTT) program.

The PDS is designed to “provide continuous detection capabilities in high-risk areas,” including finding links to existing infrastructure and locating within a certain degree of accuracy the point where a tunnel crosses the border, DHS explains. Border Patrol agents also use it to “forecast the trajectory of a detected tunnel to the suspected entrance on the Mexican or Canadian side of the border, and to estimate the subsurface path to the exit point on the U.S. side of the border,” DHS says.

The contract, managed by CBP, would be awarded in the first quarter of fiscal 2026 to expand PDS operations in California and in various southwest border locations with a completion date of Dec. 31, 2026.

Expanding PDS operations will build on investigations already underway stemming from two major finds earlier this year.

In April, CBP San Diego Sector Border Patrol Tunnel Team agents uncovered and disabled a large-scale narcotics smuggling tunnel linking Tijuana, Mexico, to the San Diego area.

The tunnel ran under part of the CBP San Diego Sector Otay Mesa Port of Entry. Although unfinished, it measured nearly 3,000 feet long, 42 inches high, 28 inches wide and ran approximately 50 feet underground at its deepest point, authorities found.

When Border Patrol agents first went inside, they found multiple makeshift barricades, placed haphazardly “in an apparent effort to impede agents’ southbound progress and the eventual identification of the tunnel’s origin.”

They discovered that it extended more than 1,000 feet inside the U.S., “was highly sophisticated” and “equipped with electrical wiring, lighting, ventilation systems, and a track system designed for transporting large quantities of contraband,” Border Patrol agents found.

In California, Border Patrols agents estimated the tunnel’s exit point was near or within a nearby commercial warehouse space. In Mexico, working with Mexican officials they determined its entrance was located inside a residence in the Nueva Tijuana neighborhood. Mexican authorities served a warrant at the location and identified the entrance, which was concealed by tile.

CBP San Diego Sector Acting Chief Patrol Agent Jeffrey Stalnaker said it wasn’t surprising that foreign terrorist organizations resorted to using underground routes and the Border Patrol agents were in a dangerous situation the further they went into the tunnel.

The Sinaloa Cartel, which has controlled the Mexican region south of San Diego for decades, has long used a tunnel system to reach the San Diego area, authorities have told The Center Square. Since 1993, San Diego Border Patrol agents have found more than 95 tunnels in the area and destroyed them by pouring thousands of gallons of concrete inside.

In January, Border Patrol agents in the CBP El Paso Sector also discovered a man-made tunnel stretching from Ciudad Juárez, Mexico, into a public storm drainage system in El Paso.

Border Patrol agents found the tunnel was braced with wood beams throughout, measured six feet tall and four feet wide and was equipped with lighting and a ventilation system.

“Our agents are relentless in searching and surveying every square mile of the El Paso Sector,” El Paso Sector Chief Patrol Agent Anthony Scott Good said. U.S. and Mexican authorities also worked together to remediate the tunnel.

Border Patrol’s discovery and disruption of the tunnel “underscores the vital importance of coordination and collaboration among our law enforcement agencies … to combat illegal criminal activity and address national security threats,” FBI El Paso Field Office Special Agent in Charge John Morales said. The FBI has long warned that El Paso is a key smuggling hub known for kidnapping, gang and foreign terrorist violence, The Center Square reported.

Border Patrol is requesting assistance from the public to combat border crime. El Paso residents are encouraged to report suspicious activity or potential smuggling operations by calling 1-800-635-2509 or WhatsApp (915) 314-8194. San Diego residents are encouraged to call 619-498-9900. Reports are anonymous.