Though native mostly to the Sierra Nevada and Coast Ranges between San Francisco and Oregon, California black oak, Quercus kelloggii, also inhabits isolated colonies in lower mountains as far north as the southern half of the Oregon Coast, and as far south as San Diego County. It actually occupies more area than any other hardwood tree in California. Wild trees competing in forests can get more than a hundred feet tall and live for five centuries. Well exposed urban trees may take their first century to eventually get about half as tall with trunks as wide as four feet.

Even while young, California black oak is a distinguished tree, with a broadly rounded canopy and elegantly arching limbs. The smooth silvery bark of young trees eventually becomes dark and uniformly checked with maturity. The distinctive deeply lobed leaves are about five inches long, and turn gold, soft orange or even brownish red before falling in autumn.