Texas Border Patrol agents seized 7,828 pounds of pot during a truck inspection near Laredo Thursday morning.
Agents said they were checking the driver during an immigration check along Interestate 35 when a drug-sniffing dog alerted agents to the drugs.
When agents opened the trailer they found 264 bundles containing marijuana.
Investigators said the pot has a street value of $6.2 million.
The driver is in custody and could face felony drug smuggling charges.
