Published by the American Geophysical Union as part of the Field Trip Guidebooks Series, Volume 117. Field Trip T117 is designed to present a variety of Quaternary geological studies from a part of the American Southwest. Specialties within the broad scope of “Quaternary geology” that will be discussed include archaeology, climatology and paleoclimatology, geochemistry, geomorphology, paleoecology, paleontology, pedology, sedimentology, stratigraphy, tectonics, and volcanology.