The Central Valley has rocks and oil, but its geology also includes water and fossils. See them in this side trip during your next drive south.
Imagine a vast grassy plain covered with herds of elephants, bison and camels stretching as far as the eye can see. Lions, tigers, wolves and later, humans, hunt the herds on their summer migration. Africa? No, the Bay Area. During the close of the last Ice Age. Take a trip back 20,000 years, to a time when San Francisco Bay was just a riverbed and local wildlife looked a whole lot different.
The rocks, long known as the "Sunset Boulders", have attracted rock climbers for years. I've climbed these rocks before. But like so many other people, I had no idea I was touching history. During the Pleistocene, 10 to 20,000 years ago, this place was very different than it is today, inhabited by massive mega-fauna; bigger elephants, lions, bears and wolves, than we see today.