Deadwood Police Sgt. Joe Leveque stopped a 1993 Nissan driven by Carlos Salazar Jr, 29, of Phoenix, Ariz., near the Lower Main Street Parking Lot about 11:15 p.m., said Fuller.
Leveque became suspicious and Fuller said Little and Mica were called in to give the truck the "once over."
Mica indicated the scent of drugs was present near the rear bumper area, he said.
A check under the truck in the rear of the bed area found modifications to the vehicle, Fuller said.
Officers removed the pickup's tailgate and discovered an access panel behind the rear bumper that led to a four-inch false bottom to the bed of the truck. That's where they found 32 packages of marijuana, the police chief said.
Salazar was arrested on suspicion of possessing more than 10 pounds of marijuana and possession of marijuana with intent to distribute, said Fuller.
He was being held Tuesday at the Lawrence County Jail in Deadwood, Fuller said.
Fuller said this was the largest pot bust in the history of the Deadwood Police Department.
He commended the close cooperation of the police department and sheriff's office, and said the case illustrates the success of training law enforcement officers.