Underground Passage Found Connecting Tijuana and San Diego Raises Questions

The U.S. Border Patrol’s San Diego Sector has uncovered another sophisticated cross-border smuggling tunnel. Criminal organizations increasingly turn to subterranean methods, prompting intensified collaborative efforts between U.S. and Mexican authorities to detect and neutralize these illicit passageways. How has tunnel activity along the border gone undetected?

Sophisticated Tunnel Network Exposed

In early April, the San Diego Sector Tunnel Team discovered an incomplete but highly sophisticated drug-smuggling tunnel extending from Tijuana, Mexico, into the Otay Mesa area of San Diego. The tunnel ran directly beneath the Otay Mesa Port of Entry, stretching over 1,000 feet into U.S. territory with a total length of 2,918 feet.

The engineering behind the tunnel demonstrated considerable resources and planning, featuring electrical wiring, lighting systems, reinforced walls, ventilation, and a rail track system designed for efficient contraband transportation. At 42 inches high and 28 inches wide, the passage reached depths of approximately 50 feet underground, making detection from above nearly impossible.

BREAKING: Border Patrol agents shut down massive 3,000-foot drug smuggling tunnel between Tijuana, Mexico and San Diego, equipped with lighting, ventilation systems and tracks to move narcotics

The agents discovered the tunnel in early April while it was ACTIVELY under… pic.twitter.com/7qiLnAlLke

— Libs of TikTok (@libsoftiktok) June 19, 2025

Collaborative Cross-Border Enforcement

Border Patrol agents encountered makeshift barricades placed strategically throughout the tunnel, apparently intended to hinder their progress and conceal the tunnel’s origin point. Working alongside Mexican authorities, officials traced the tunnel back to its starting point in a Tijuana residence, where the entrance had been cleverly concealed beneath freshly laid tile.

Jeffrey D. Stalnaker, Acting Chief Patrol Agent of the San Diego Sector, highlighted the significance of the discovery: “As we continue to strengthen the nation’s air and maritime border security, it’s not surprising that foreign terrorist organizations would resort to underground routes. Disruption of narcotics smuggling tunnels is critical to protecting American lives.”

Mexican authorities said that a clandestine tunnel connecting the United States and #Mexico underground was discovered, amid pressure from Washington to curb drug trafficking between the nations, mainly the deadly #fentanyl. The tunnel, was 13.5 meters deep and approximately 600… pic.twitter.com/bkecFuQHAO

— DD News (@DDNewslive) June 20, 2025

Growing Underground Threat

This discovery represents the latest in a concerning trend of subterranean border breaches, with over 95 tunnels found and decommissioned in the San Diego area alone since 1993. Authorities plan to fill the tunnel with concrete to permanently prevent its potential use by drug cartels or foreign terrorist organizations.

The newly discovered passage is not even the most impressive example of subterranean smuggling infrastructure found in recent years. In 2020, the Drug Enforcement Administration uncovered what remains the longest cross-border tunnel on record, stretching an extraordinary 4,309 feet from Tijuana into the United States, featuring its own elevator and rail system.

Since 1990, federal agencies have discovered more than 140 tunnels breaching the U.S. border, with activity increasing by approximately 80% since 2008. The House of Representatives has responded to this growing threat by passing the Subterranean Border Defense Act, while current U.S. law imposes severe penalties for tunnel-related activities, including prison terms ranging from 10 to 40 years for building, knowing about, or using such border tunnels.

Sources:

• San Diego Sector Border Patrol uncovers sophisticated cross-border drug smuggling tunnel

• Border Patrol Finds Tunnel From Tijuana Into San Diego; At Least Second Long Tunnel Found This Year – The New American