Clear Lake in Northern California might appear from the outside just like any other lake surrounded by vineyards and towns, yet USGS and UC Berkeley summaries of its sediment cores describe it as one of the oldest lakes in North America, with a basin that has been collecting sediment for up to roughly 500,000 years. It hides, however, an extraordinary feature in its depth: USGS researchers have documented a basin where sediment layers have accumulated for hundreds of thousands of years without ever fully draining or freezing over. This largely continuous sediment sequence made this lake an important location in North America for studies of forest history in California, including the redwood group.
Clear Lake’s basin has preserved sediment for roughly 500,000 years
