BADIRAGUATO, Mexico -- As a child, Joaquín Guzmán Loera was so poor that he sold oranges to scrape together money for a meal. Since then, the 52-year-old has built a business empire and a personal fortune currently tied for number 701 on Forbes magazine's list of global titans.

He also has another ranking: Mexico's most wanted man.

Mr. Guzmán is the informal CEO of one of the world's biggest drug-trafficking organizations, the so-called Sinaloa cartel, named for its home state of Sinaloa. It smuggles a big part of the marijuana, heroin, cocaine, and methamphetamines that end up on American streets, and it has links to organized crime in 23 countries, according to Mexican and U.S. officials.

Mr. Guzmán's rivalries and turf wars have contributed to a drug-war death toll that stands at 11,000 in the past two and a half years, an average of 366 murders per month. His feuds stretch back more than two decades, leaving a trail of tombstones that act as milestones of the narcotics business south of the border.

Part Al Capone and part Jesse James, Mr. Guzmán has become a narco folk hero. He is feted on YouTube videos and by musicians who pen ballads, known as corridos, in his honor. He is known throughout Mexico simply as "El Chapo," Mexican slang for a short and stocky man.