If you'd been here hundreds of thousands of years ago, before the Lassen volcano first arose, the view in this direction would have been quite different. You would have been looking up at the much larger Mount Tehama volcano -- of which Lassen was originally "just" a side vent.

Where'd it go? Well, a few collapses and glaciers later, only its outline remains, in the form of a huge ring of smaller peaks behind and to the right of Lake Helen. Wow.