Crater Lake should actually be called Caldera Lake, given that it's the remains of a massive volcano that exploded 10,000 years ago (or it might have been less. But there was almost certainly ancient indigenous humans nearby to have witnessed it.

If they were nearby they didn’t witness it for long.

We thought it was a volcanic crater rather than a caldera. (That said, those are pretty closely related, and the main differentiating element is size)