In La Paz Agreement, the United States-Mexico border region is defined as the area of land being 100 kilometers (62.5 miles) north and south of the international boundary. It stretches approximately 2000 miles from the southern tip of Texas to California. The population for this stretch of land is estimated to be approximately 15 million inhabitants. This population is expected to double by the year 2025. The combined population of Texas, New Mexico, Arizona and California is 70,850,713 (2010 Census). The estimated combined population of the six Mexican border states is 19,894,418. Two of the ten fastest-growing metropolitan areas in the United States - Laredo and McAllen - are located on the Texas-México border. Additionally, there are 154 Native American tribes totaling 898,770 Native Americans living in the four U.S. border states. In the actual border region, there are approximately 25 Native American Nations.
This is a dynamic region that is medically underserved with professional health shortages that serve a population that has pressing health and social conditions, higher uninsured rates, high rates of migration, inequitable health conditions and a high rate of poverty. The border area comprises:
- Two sovereign nations
- Four states in the United States and six states in México
- A total of 44 counties in the U.S. and 80 municipalities in México
- 15 pairs of sister cities