Topography The region is bounded by the
Santa Cruz Mountain Range, from the northern boundary of
Half Moon Bay and
Woodside to its southern side of
Mount Madonna and
Watsonville. The appellation encompasses some extending through
Santa Cruz,
Santa Clara and
San Mateo counties. The boundaries of the "Santa Cruz Mountains" viticultural area are based, in general, on contour lines and man-made features. Evidence was presented at the hearing that the contour lines varied to different levels to include an area exhibiting the same general geophysical characteristics, e.g. climate, soil, and topographic features. Portions of the boundaries of the viticultural area are marked by man-made features, e.g.
Highways 280 and
84, and Cañada Road to the east. These roads were chosen because they delimit the particular geographical and climatic features of the area.
Climate "Santa Cruz Mountains" is characterized by a climate which is greatly influenced in the western portion by the Pacific Ocean breezes and fog movements, and in the eastern portion by the moderating influences of the San Francisco Bay. These two influences tend to produce weather which is generally cool during the growing season. Temperatures in the slopes of the hillsides where most of the vineyards are located appear to vary from that at the lower elevations. This is caused by the marine influence coming off the Pacific Ocean which cools the mountains at night much more than the valley floor. The area is characterized by a growing season in excess of 300 days. This is
air drainage due to cool air coming down the mountains forcing the warmer air upward, thereby lengthening the season in which the necessary conditions for grape-growing are present. Moreover, while the climate, in terms of temperature can be characterized as mild, the "Santa Cruz Mountains" has an average rainfall much greater than the surrounding areas.
Soil The soils in the area were identified as
Franciscan shale which is unique to this particular area south of San Francisco. The soil is basically residual material from the decomposition of bedrock and the soil types in the area differ depending on the type of underlying bedrock. Generally, these residual soils tend to be thin and stony, and somewhat excessively drained. They were characterized as impoverished. making it extremely difficult to grow grapes. This contrasts greatly with the soil of the surrounding area which is primarily alluvium and is more fertile. ==Wine regions==