New Mexico is a state located in the southwestern region of the United States. The eastern border of New Mexico lies along 103° W longitude with the state of Oklahoma, and three miles (5 km) west of 103.5° W longitude with Texas. 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 western border with Arizona runs along the 109° 03\\\' W longitude.