The Chihuahuan Basin, also known as the Chihuahuan Divide Basin, is a vast, arid, high elevation endorheic (closed) basin characterized by desert topography and located east of the primary hight of land known as the continental divide in North America.

The Chihuahuan Basin normally has hot summers, cold winters and internal drainage in which most rainfall evaporates rather than drains to the ocean. This is the most biologically diverse desert in the Western Hemisphere, positioned between the Sierra Madre Oriental and Occidental ranges. The precipitation is low and averages from 7 to 20 inches per year.

The Chihuahuan Basin, contained within the much larger Chihuahuan Desert is designated as part of the basin-and-range topography, and features broad, arid valleys (basins) located between fault-block mountains. Internal drainage in these low-lying areas often forms ephemeral playas, which are temporary, shallow, and saline lakes form following rare heavy monsoon rains. These environments typically contain fine-textured soils, salt crusts, and hardy vegetation such as Atriplex species.

The Chihuahuan Divide Basin is an endorheic, or internal drainage basin out of which there re no rivers or streams that drain to the sea, but rather toward the center of the basin, often terminating in swamps and ephemeral lakes.

It is located in the north-center of the Mexican Plateau, which lies between two Northern Sierra Madre ranges, the eastern Sierra Madre Oriental range and the western Sierra Madre Occidental range and contained within the Mexican states of Durango, Chihuahua, Coahuila, Nuevo Leon San Luis Potosi and Zacatecas.

The Chihuahuan Divide Basin, in which is contained a smaller basin known as the Bolsón de Mapimí, a region about 50,000 square miles which is sparsely populated. The Bolsón is bounded on the west by the Sierra Madre Occidenta and the Chonchos River watershed, on the north by the Rio Grande watershed,