In Arizona, Border Patrol encounters new tactics in migrants' bid to cross into US

Just south of Tucson, Arizona, lies one of the most treacherous stretches of the US-Mexico border: 262 miles of hot, dry, often mountainous terrain.

Patrolling this area -- which encompasses some 90,000 square miles -- is the responsibility of US Border Patrol Tucson Sector, who we joined for several days of air and ground operations. Despite the landscape, Border Patrol is seeing a dramatic rise in attempted crossings from Mexico, Central and South America. Encounters are up more than 150% this year from the same period last year. And detections by the Border Patrol's drones monitoring the area from the air have tripled in the same time period, the agency says.