The Shoo Fly Complex, northern Sierra Nevada, California has been subdivided into, from structurally lowest to structurally highest, (1) the Lang-Halsted sequence, (2) the Duncan Peak chert, (3) the Culbertson Lake allochthon and (4) the Sierra City melange. Northeast-dipping thrust faults bound each structural slice, and stratigraphic patterns in the Culbertson Lake allochthon suggest that at least parts of the Shoo Fly Complex form an imbricate structure that formed in a Paleozoic accretionary complex. If this hypothesis is correct and can be expanded to include other units in the Shoo Fly Complex, then each fault-bounded slice contains information about how the accretionary complex evolved. We will undertake a two-year program to investigate the age(s) of chert units throughout the Shoo Fly Complex, and the stratigraphic, petrologic, sedimentologic, and structural characteristics of the Lang- Halsted sequence. Data generated by work proposed here will allow for a comprehensive terrane analysis of a complete cross- sectional portion of the Shoo Fly Complex, and will add significantly to our understanding of the most extensive belt of lower Paleozoic rocks in California. The results could have a major impact on the distribution of aboriginal North American crust and exotic or suspect crustal elements.