Northern Mexico's smallest towns are experiencing an exodus of people who feel threatened by drug cartel violence.

The diaspora along the U.S. border is leaving villages in Sonora, Chihuahua and Tamaulipas all but empty, left to turn into lawless ghost towns. In the hills of northern Sonora, residents say the government can no longer protect them.

In the mission town of Tubutama, which is more than 300 years old, Father Anastasio Franco Gómez says two-thirds of the town's population has fled. Violence began there more than a year ago, and ever since, people have quietly left the community.

Locals warn not to go too far into the hills. Even the Sinaloa Cartel stays out, as does the Mexican army. They circle the region instead.