This study utilizes enhanced Landsat Thematic Mapper (TM) images in concert with field work to solve problems in regional correlation of Miocene rocks in the Colorado River extensional corridor of California and Arizona. These syntectonic volcanic and sedimentary deposits preserve a dateable record of crustal extension, although regional correlation and analysis of the deposits are difficult because of the small sizes of the sedimentary basins in which they accumulated and disruption by postdepositional faulting. Based on field investigations, four sequences of sedimentary and volcanic strata, distinguished by stratigraphic and structural relations, can be recognized in the Mohave Mountains, Arizona, and the eastern Whipple Mountains, California. Although the sequences are found in each of four structural regions, the relative volumes and organization of lithologies within the sequences differ considerably between regions. These sequences have distinctive appearances on the TM image. The volcanic component is particularly important in distinguishing between regions and sequences because differences in color and textural patterns in the image are usually related to variations in the proportion and composition of the volcanic material and in the geometry of the volcanic bodies. The recognition criteria derived from field mapping and image interpretation in the Mohave and Whipple Mountains were applied to an adjacent area in which stratigraphic affinities were less well known. Stratigraphic and structural relations suggested by the TM image were confirmed by subsequent field work. ¿ Amerigan Geophysical Union 1990