Cartel City, Arizona (S04E09)

Phoenix, Ariz., is the wholesale drug capital of America, under the control of one of Mexico's most powerful and ruthless drug organizations ' the Sinaloa Cartel. Almost 200 miles north of the Mexican border, the city has become the major stopping off point for the large-scale distribution and transshipment of marijuana, heroin and methamphetamine up from Mexico and out to the rest of the country. (National Geographic)