Valley oak is the largest and tallest of all North American Oaks. Unique to California’s Central Valley and Sierra foothills, it prefers rich, deep soil associated with stream and river floodplains. Early settlers discovered that Valley oaks were indicators of prime soils, ideal for farmland. Today, major cities in the Central Valley (Visalia, Stockton, Sacramento and Chico are established where large Valley oak groves once existed. Only a small percentage of the trees that formerly covered the valley remains and most of the present grows lack saplings and seedlings. An unanticipated factor contributing to the demise of the oaks has been the construction of dams on major rivers draining into the central valley. These prevent massive winter and spring floods, formerly responsible for delivering nutrient-rich silt to the Valley oak forest. The current decline of the valley oak is due mainly to changes in land management use.