The drugs were packed into a semi-truck and livestock trailer and they were valued at more than $2 million.
The seizure began around 8 p.m., when Sonoita Station agents alerted Willcox agents of the suspicious vehicle.
A news release from U.S. Customs and Border Protection revealed more.
A tractor-trailer carrying livestock approached the primary inspection area where agents noticed the ventilation holes in the upper compartments of the cattle hauler were plugged. Further inspection led to the discovery of 188 bundles of marijuana and a pistol. The driver was arrested. The marijuana, firearm and tractor-trailer were turned over to the Drug Enforcement Administration.
Border Patrol agents in the Tucson sector have now seized more than 772,000 pounds of marijuana since the beginning of the 2014 fiscal year.