As applause rang out at a nearby international arts festival, Bibiana Mendoza unearthed human remains from a clandestine grave in a Mexican region where prosperity, culture, and cartel violence converge.The 32-year-old woman, who is looking for her missing brother, arrived at the site in the town of Irapuato in Guanajuato state after residents reported seeing a dog carrying a human hand in its mouth.Cartel turf wars have given Guanajuato the unenviable title of Mexico's most violent state, with more than 2,400 murders from January to September of this year -- almost 10 percent of the national total.Industrial hubMazda's plant in Salamanca -- its largest outside of Japan -- runs like clockwork producing around 815 vehicles a day, some for export.Guanajuato is an important corridor along drug smuggling routes between Pacific ports and the United States, according to security expert David Saucedo"It's part of the fentanyl and cocaine routes," he said."