Border Patrol agents seized a truck designed to look like a U.S. Fish and Wildlife Service vehicle along with a flatbed trailer containing more than 3,200 pounds of marijuana near Douglas on Monday.
The agency said the drugs are worth about $1.6 million.
Agents working east of town responded to reports of suspicious activity and found a truck driving along the international boundary fence. The truck stopped and two people inside got out and ran into Mexico, Customs and Border Protection said in a news release.
They had removed a 1000 lb vehicle barrier and replaced the barrier when on the US side not to draw suspicion.
Agents searched the truck, which had fake decals from the federal wildlife service, and found the hidden bundles of marijuana in the trailer.
The vehicle and drugs were seized.