Backed by good intelligence, the smugglers constantly devise new methods to get their goods over the border. Agent Mason cites smugglers who tunnelled under the border into the sewer system on the American side. In urban areas where homes are built right up to the border fence, smugglers simply toss softball-sized packages of heroin or cocaine into American backyards, where colleagues snatch them up and walk on. Last year, a Border Patrol truck travelling on a remote dirt road suddenly dropped into a sinkhole. The truck had fallen into a tunnel complete with concrete walls, a railway track and a cart to shuttle drug loads back and forth.
Officials have no idea how long it was in use.
The gate was discretely hinged on the Mexican side, and tire tracks from trucks using the gate were carefully swept away after each use, so nothing looked amiss. Again, it's not known how long, or how often, the gate was used. They're as intuitive and creative as we are at coming up with ways to solve a problem. Every time we come up with a new method of dealing with something, they come up with a new way to smuggle. Smugglers responded with compartments within the tires so tapping would hit hollow sections.