Twilight in the Northern Bristol Mountains

Rain clouds at twilight over the Norhtern Bristol Mountains. THese types of winter storms provide water to the desert ecosystem, but are not usually intense enough to transport sediment or do other geomorphic work. This image was captured during geologic mapping of surficial geologic materials in order to better understand the Quaternary (younger than ~2.5 million years) history of faults in the Eastern California Shear Zone. This wide swath of distributed faulting and deformation accommodates some of the relative motion between the Pacific and North America Plates that does not occur on the San Andreas Fault system.