The Mexican drug cartels are fighting to keep up with the increased border protection. In the past couple of years, the United States border security has increased dramatically inspecting vehicles both coming into and leaving the U.S. As a result, the Mexican drug cartels have built many tunnels used for smuggling drugs into the U.S., and weapons into Mexico.
Since 2008, authorities have found 70 tunnels in the United States and Mexican border. Over time, these tunnels have become increasingly sophisticated equipped with ventilation, electricity, and sometimes even a railcar system.
In July 2012 alone, authorities found three highly sophisticated tunnels connected to Mexico, two in the San Diego, CA area and one in San Luis, AZ. One of the tunnels connected to San Diego included a lighting and railcar system. The tunnel found in San Luis was equipped with ventilation, electricity, and was tall enough to fit a person standing.
After the discovery of these tunnels, DEA released a statement in which they noted that the degree of sophistication requires engineering experts. Each tunnel takes anywhere from 6 months to 1 year to complete, and they cost over a million dollars each. However, the amount of drugs cartels have been smuggling is extreme. Mexican authorities found 40 tons of Marijuana at the entry of a San Diego tunnel connected to Tijuana, Baja California Mexico. In Arizona, DEA seized a truck containing 39 pounds of meth, which they believed was smuggled through the tunnel found in San Luis, AZ.