Why hasn't SV built out towards the west and the pacific ocean and instead built downwards? There seem to be big swaths of unused space there, and for such an expensive place it seems a bit strange.
The northern coast is more like a milder version of Oregon. Redwood tree habitat continues all the way down to around Monterey along the coast. Foothills separate the coast from the Central Valley, which is ideal agricultural land but tends toward extremes of weather. Go farther east and you hit the Sierra foothills - the center of the Gold Rush. It becomes forested again and you'll see a fair number of one-street towns and two-lane highways. And then going over the mountains gets you to Nevada.