Two factors have changed the usual patterns of drug smuggling on the Mexican border, says the Los Angeles times. First, drug cartels in Mexico are in a deadly battle over smuggling routes into the United States. At the same time, more border agents, hundreds of miles of new fencing and a growing arsenal of high-tech devices have made it harder than ever for drug traffickers to cross much of the 2,000-mile border with Mexico.
The crackdown has driven waves of ever more daring smugglers to the most remote and rugged parts of the border, areas that are difficult for federal agents to patrol, where fancy electronic surveillance is often useless. The southwestern corner of New Mexico, with its 81 miles of border, is one of those prime corridors, a forbidding area where drug traffickers find plenty of places to hide. To outwit their adversaries, Border Patrol agents here rely on tracking skills borrowed a century ago from Native Americans: “cutting for sign,” detecting where someone has crossed the Earth’s surface, and “pushing sign,” tracking that person down.