The heavily wooded scrub vegetation, or chaparral, of the inland foothills is typical of many areas of California. Occurring on the western slopes of the mountains at elevations of 1,000 to 4,000 feet and along the eastern mountain slopes (desert side) at elevations of 3,500 to 5,000 feet, this elfin forest presents an impenetrable thicket of shrubs and small trees.
The southern oak woodland occurs in valleys and adjacent rolling hills throughout the chaparral in southern California. The rainfall varies from 15 to 30 inches with most of the precipitation occurring during the winter months. Some moisture persists in the higher elevations as snow; however, much of the water is lost through runoff. The number of frost-free days averages from 350 in lower elevations to 200 in the higher mountains.

*Extracted Natural History of Southern California: Ancinec, Radford, Schwenkmeyer