[from the text] The foothill range lands of California are located both in the Coast Ranges and in the Sierra Nevada-Cascade Mountains, comprising a discontinuous zone between the upper limits of the valley floors and the lower limits of those forests that produce commercial timber. For the most part they lie between elevations of 500 and 2,500 feet above sea level. Soils, climate, physiography and other conditions affecting plant growth, vary widely. The lower slopes of these foothills are rolling grasslands; there is a transition to oak-grass woodland and chaparral at higher elevations and on more rugged terrain. While the grassland is relatively distinct, the woodland and chaparral are much intermingled (Fig. I).