Twenty-thousand years ago, during the Late Pleistocene age, megafauna like giant bears, fearsome saber-tooth cats, massive sloths, and monstrous mammoths roamed the forests of what’s now known as China Camp State Park. We can only imagine what one of these animals would have seen as it gazed eastward from a rocky perch atop San Pedro Ridge.

Research shows these enormous creatures would not have seen a sparkling bay, but rather a network of rolling valleys and deep river channels that eventually emptied into the ocean, 20 miles west of where the Golden Gate is today. At the time, sea level was much lower than today, as much ocean water was frozen into Ice Age glaciers. How and why were there so many drastic changes to the landscape since then? 

During this invigorating hike, naturalist Harold Hirsch will address this question. He’ll also offer an overview of the geology and biology of China Camp within the broader context of Marin and California’s natural history. This hike will have excellent views of the park’s salt marshes, the North Bay, and the Coast Range. Bring a full water bottle, snacks, hat, and sunscreen. Wear proper hiking shoes and bring layers for changeable weather.