Drug Seizures at the U.S. Border

How Drugs Cross the Border

Contrary to popular perception, the majority of hard drugs — especially fentanyl and cocaine — enter the United States through official ports of entry, not between them. Drug traffickers hide narcotics in passenger vehicles, commercial trucks, and cargo shipments passing through CBP inspection at legal border crossings.

U.S. Border Patrol (operating between ports) seizes more marijuana, while the Office of Field Operations (at ports of entry) intercepts the majority of fentanyl, meth, and cocaine. This distinction matters for policy: border walls primarily affect between-port crossings, while drug interdiction depends on scanning technology, intelligence, and inspection capacity at the ports themselves.

The Fentanyl Supply Chain

Most illicit fentanyl is manufactured in Mexico using precursor chemicals sourced primarily from China. Mexican cartels — primarily the Sinaloa Cartel and Jalisco New Generation Cartel (CJNG) — operate large-scale production labs and smuggle finished product across the southwest border.

Fentanyl is extremely profitable to smuggle because of its potency-to-weight ratio. One kilogram of fentanyl can generate $1-2 million in street revenue, compared to $25,000-$50,000 for a kilogram of heroin. This economics has driven the near-complete replacement of heroin with fentanyl in the U.S. drug supply — visible in our data as heroin seizures plummeted while fentanyl surged.

Seizures vs. Flow

CBP estimates it intercepts only a fraction of total drug flow. Seizure data tells us what wascaught, not what crossed. Increases in seizures can indicate either more drugs flowing or better detection capabilities — often both simultaneously.