An investigation uncovered that human trafficking networks in El Paso have adapted to border enforcement by routing migrants through the city's network of underground storm drains, which connect across the Mexico-US boundary. This infrastructure has become a primary smuggling corridor for cartel operations seeking to move people and narcotics into the United States.

The underground passages subject migrants to severe hardships, including extreme heat, complete darkness, and severely restricted space. Current smuggling operations charge between $20,000 and $30,000 per person for transit through these tunnels, creating a high-cost and high-risk mechanism that exploits vulnerable migrants while generating substantial revenue for trafficking organisations.