The Rio Grande Rift is a rift valley extending north from Mexico, near El Paso, Texas through New Mexico into central Colorado.

The area is presently quiescent, but significant geological activity has occurred in the area over the last 30 million years. The rifting involves a pure-shear rifting mechanism, in which both sides of the rift pull apart evenly and slowly, with the crust stretching like taffy rather than fracturing.