One of the largest of North American oaks. It is endemic to California, growing in interior valleys and foothills from Siskiyou County to San Diego County where it is most abundant in rich deep soils of valley floors below 600 meters in elevation. Mature specimens may attain an age of up to 600 years. This deciduous oak if given access to year-round access to groundwater will tolerates cool wet winters and hot dry summers.
