California: Geography

California’s wine regions extend over more than 600 miles/960 km of the state’s 900-mile length from north to south. They also extend 135 miles west to east from the Pacific coast up into the Sierra Nevada Mountains. It is therefore difficult to typify soil types in California’s vineyards because so much of the state’s landforms have been emplaced on the North American tectonic plate, and then crumpled together by the action of the Pacific tectonic plate’s sliding beneath it. Most vineyards have intrusions of several different soil types. Hence identification, and separate vinification, of different blocks within vineyards (see precision viticulture) became an increasingly valuable tool in the early 21st century for California’s most quality-conscious winemakers. Until this century it was rare for wines from separately vinified vineyard blocks to appear as such in the market place; most were blended (for complexity) at the winery into a range of styles and price levels more easily understood by consumers. But by the second decade, single-vineyard, single-block, and/or single-clone bottlings proliferated, albeit produced in small amounts and typically restricted to Chardonnay, Pinot Noir, Cabernet Sauvignon, and Merlot.