Napa’s climatic and geographic strength is her progression of cool and damp conditions in the south to hot and dry conditions in the north with a plethora of soil types from gravel and low fertility in the north to clay and silt in the south.  While she does not have Sonoma’s diversity in microclimates, Napa does have good range of soils and elevation that positively affects the fruit she produces.  Like in Sonoma, Los Carneros allows for sparkling wine production, while Howell Mountain, Oakville, and Rutherford all produce most of the regions award-winning and high-class Cabernets.  Napa Cabernet, after all, is what made this US region so famous.  Both regions are clearly blessed with natural conditions and topography that allow for certain varietals to thrive, with this in mind let me move forward to the issue of varietals.