The Mountains and Basins region has the highest elevation and is bordered by the Rio Grande River on the south. It also includes the Pecos River, as well as Big Bend National Park, which showcases mesas and canyons. This region contains the highest point in Texas, Guadalupe Peak, is in this region.

This region receives the least rain in Texas, only 8 inches per year, and it is mostly desert. The Mountains and Basins region has hot summers and mild-to-cool winters. However, the higher one travels in elevation, the colder it becomes, so this region also includes snow-capped mountains.

The economy of the Mountains and Basins Region relies on farming along the Rio Grande River where cotton is the primary crop. It also has oil and gas reserves, and tourism is a major industry as people travel to see the scenery and visit the McDonald Observatory, which hosts "star parties," opportunities to view the night sky through its many telescopes.

El Paso is the largest city in this region. It is a border town with Juarez, Mexico, and enjoys a strong Latino culture.