If you want to be a geological fancy pants, Crater Lake should be called Caldera Lake. A caldera is the depression formed by the collapse of a volcano. In this case it was Mount Mazama. I had assumed the caldera formed hundreds of thousands of years ago, but it was recent enough that the collapse might have been witnessed—or certainly felt—by humans. Seventy-seven hundred years ago was just last night in geologic time.
What the bottom of Crater Lake looks like
Why the dissertation on Crater Lake? I passed through there on my way to Redmond to join up with Lou.