In France, the concept of terroir — the idea that a place leaves its mark on everything grown within it — gave rise to appellations: legally defined regions where specific grapes thrive because of the precise combination of soil, climate, and geography. In the United States, these regions are known as AVAs — American Viticultural Areas. Sonoma County has nineteen of them. Each one is a distinct world unto itself, shaped by its proximity to the Pacific, its elevation, its soils, and the way fog moves — or doesn’t — through its valleys. To understand Sonoma’s wines is to understand its land. What follows is a guide to that land.
