Your average U.S. truck driver in the makes something like $.30 or $.40 cents per mile. It's enough to make a living but not much else.

Swap the 18-wheeler full of widgets for one full of Mexican marijuana, and the job becomes way, way more lucrative. Reliable data are tough to come by -- this particular sub-occupation isn't tracked by the Bureau of Labor Statistics, and it's not a topic that comes up in online trucking forums -- but anecdotally, a driver transporting weed can make $50,000 for a 430-mile trip, or roughly 300 times his law-abiding counterpart.

That's at least the amount that was offered last week to an undercover law enforcement officer in Laredo for the eight-hour drive to Dallas.

See also: Denton County Police Discover That They Make Marijuana Candy and Soda Now

According to a federal criminal complaint filed in Dallas on Monday, Homeland Security investigators learned on March 24 that a Laredo-based drug-trafficking ring was looking for someone with a commercial driver's license to take a shipment to Houston or Dallas. Through their contacts, the investigators suggested the undercover officer could take the job.

The cop, who isn't identified in the complaint for obvious reasons, spent the next three days arranging the shipment. On March 27, he met Victor Manuel Gonzalez and Benito Gonzalez in a Walmart parking lot, then followed them to a truck storage yard off Interstate 35, directly across the highway from a complex containing offices for the FBI, DEA and Border Patrol.

Inside was a white, refrigerated trailer containing 1,000 pounds of marijuana. He would be paid $50 per pound upon completion of the trip, plus $1,700 up front to cover expenses.

The cop stopped for the night in front of a San Antonio Walmart, where San Antonio police and their drug dog, Swampy, confirmed that the 18-wheeler was indeed full of drugs. The next day, the officer completed the trip to Dallas.

Victor and Benito Gonzalez, along with a third man, Rodrigo Moreno-Gaona, were waiting for him at the Flying J truck stop on I-20 and Bonnie View Road when he rolled in at 2:30 Friday afternoon. They were driving a Chevrolet Suburban with Mexican plates, the same one the Gonzalezes had been in the previous day, with which they led him to Michoacana Body Shop in Wilmer. There, they handed the cop a large bag containing $49,820 in cash.

Homeland Security agents watched all of this, moving in to seize the trailer once the undercover officer had left. Both Gonzelezes and Moreno-Gaona were arrested on charges of conspiring to distribute more than 100 kilograms of marijuana.

Send your story tips to the author, Eric Nicholson.