The United States has found trying to keep its borders, especially the US-Mexico boundary, secure from drug smuggling, illegal immigration, and potential terrorism rather difficult. Although manned patrols, high-resolution cameras, ground sensors and fences are used in more populated areas - trying to keep patrols active in desolate stretches has proven to be difficult.
There is more than 700 miles of fencing along the border that spans almost 2,000 miles - with more than 18,000 patrol agents and drones helping patrol the US side of the border. The Predator B drones patrol remote mountains, rivers and canyons using high-resolution video cameras, and all data is evaluated by analysts.
"You have finite resources," said R. Gil Kerlikowske, Customs and Border Protection commissioner, in a statement. "If you can look at some very rugged terrain (and) you can see there's not traffic, whether it's tire tracks or clothing being abandoned or anything else, you want to deploy your resources to where you have a greater risk, a greater threat."