How many U.S. states border Mexico?

There are four U.S. states bordering Mexico. The four states are: Texas, New Mexico, Arizona and California. Texas shares borders with the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the southwest, while the Gulf of Mexico is to the southeast. In New Mexico, on the southern border, Texas makes up the eastern two-thirds, while the Mexican states of Chihuahua and Sonora make up the western third, with Chihuahua making up about 90% of that. The state of Arizona borders the Mexican state of Sonora south of the Gila River. Finally, California shares an international border with the Mexican state of Baja California to the south. The Pacific Ocean is on the state's western coastline. In total, the U. S. has 1,989 miles of border with Mexico.