The Great Basin in eastern Nevada and Utah has experienced a complex history of superposed Mesozoic magmatic, metamorphic, and deformational events as well as a pervasive Cenozoic ductile-brittle extensional history. Prior work has outlined important aspects of this history, and this project is a study to restore a crustal cross-section for the eastern Great Basin, by a combination of methods including 40Ar/39Ar, and U-Pb geochronology and geothermobarometry. In the study area, the Cenozoic crustal extension has exhumed middle crustal rocks, thereby providing a window into the Mesozoic and Cenozoic infrastructure of the western North American Cordillera. Results will provide accurate timing of tectonic events associated with Mesozoic convergence and with subsequent extension, which together with an accurate crustal cross- section, will allow an in depth characterization of the complex tectonic evolution of the western margin of North America.