>> you're saying we are probably being watched right now. >> right. >> reporter: by who? >> people from the opposite side, cartel members, individuals that have interest in this particular area. >> reporter: this area is called juarez valley. it's a strategic location dotted with small towns along the rio grande on the mexican side of the border. prime real estate for the cartels because it's close to the united states, a major highway, and the railroad line. >> it's easy access in and out. >> reporter: the battle between warring cartels for control of the juarez valley has been fierce. entire towns have been targeted without mercy as cartel gunmen try to secure trafficking routes, people here call this the valley of death. on the other side of these tall, steel gates is a town under siege. residents say there is a war ranging there. entire families have been chased out of the juarez valley. some have taken only what they