There have been great advances in the last 20 years in understanding the volcanic, structural, geophysical, and petrologic development of the Coso Range and Coso geothermal field. These studies have provided a wealth of knowledge concerning the geology of the area, including general structural characteristics and kinematic history. One element missing from this dataset was an understanding of the sedimentology and stratigraphy of well-exposed Cenozoic sedimentary strata - the Coso Formation. A detailed sedimentation and tectonics study of the Coso Formation was undertaken to provide a more complete picture of the development of the Basin and Range province in this area. Detailed mapping and depositional analysis distinguishes separate northern and southern depocenters, each with its own accommodation and depositional history. While strata in both depocenters is disrupted by faults, these faults show modest displacement, and the intensity and magnitude of faulting does no t record significant extension. For this reason, the extension between the Sierran and Coso blocks is interpreted as minor in comparison to range bounding faults in adjacent areas of the Basin and Range.