Major Mexican drug trafficking organizations (DTOs), including the 

Gulf Cartel, Sinaloa Cartel, and Los Zetas, are actively involved in South Texas, primarily through drug and human smuggling, enforcement, and money laundering operations. These cartels leverage local U.S. gangs for operations and are the focus of a new, dedicated federal task force. 

Key Cartel Activity in South Texas

• Dominant DTOs: The Gulf Cartel poses a primary organizational threat and is historically based just across the border in Matamoros, Tamaulipas. The Sinaloa Cartel and Los Zetas are also major players in the region.
• Operational Control: Mexican cartels have changed the dynamic of organized crime in the area, essentially relegating local U.S. street and motorcycle gangs to “contractors” who answer to them.
• Criminal Activities: Operations in South Texas involve a wide range of crimes, including:
  • Drug and human smuggling.
  • Money laundering (sometimes through legitimate businesses like oil sales).
  • Extortion, kidnapping, and assassinations.
  • Illegal firearms trafficking from the U.S. into Mexico.
  • Recruitment of minors for smuggling operations. 

Law Enforcement Response

In November 2025, a new regional Homeland Security Task Force-South Texas was established to specifically target these transnational criminal organizations. This task force is a collaboration of numerous federal, state, and local agencies, including the FBI, DEA, HSI, and ATF, aimed at enhancing coordination to disrupt and dismantle cartel operations. 

Recent law enforcement actions have resulted in:

• Major arrests of high-level cartel leaders, such as the leaders of the Sinaloa Cartel who were arrested in Texas in 2024.
• Large seizures of drugs, weapons, and ammunition along the border.
• Indictments for money laundering and providing material support to cartels. 

For more information on border security measures and ongoing investigations, you can visit the FBI website, the DEA website, or the Homeland Security Investigations website. 

What Texas gangs do cartels use?

What crimes are associated with cartels in South Texas?

What’s the history of the Gulf Cartel and its relationship with Matamoros?