Rio Grande rift

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 quiesent, but significant geologial activity has occured in the area over the last 20 million years. The Sangre de Christo Range lie to the east of the north portion of the rift. The Colorado Plateau to the west including the San Juan Volacanic Field and the San Juan Mountains. The Rio Grande river follows the course of the rift from soutern Colorado to El Paso.