The Rio Grande rift is a major structural element of the Southern Rocky Mountain region. During the last 20 years this feature has become widely recognized as a major Cenozoic continental rift zone. During this time we have learned much about the structure and evolution of the rift. However, many gaps in our knowledge remain that prevent us from fully understanding its evolution and the processes that formed it. The rift should not be studied in isolation, because the Laramide orogeny, uplift, complex magmatism, and extension that have occurred since the Late Cretaceous are all to some extent related.