It was a little out of my way to stop by Crater Lake, but it was well worth the time. This is a freshwater lake, at about 7500 feet elevation, about 6 miles in diameter and at one point, 2000 feet deep (that's over a third of a mile!). According to Wikipedia:

on the basis of comparing average depths among the world's deepest lakes, Crater Lake becomes the deepest lake in the Western Hemisphere and the third deepest in the world. Comparing average depths among the world's lakes whose basins are entirely above sea level, Crater Lake is the deepest.

The water accumlated over the long years since the volcano Mt. Mazama destroyed itself by erupting.

It was a quite stricking to drive up and up and up, with bright white snow all around, and then come upon a crater filled with blue blue water. I'd like to go back someday when it's warm enough that I can go down to the water. I wonder if they let people swim in it?

• The outstanding view from near the Lodge
• Crater Lake Lodge itself
• Photos from other viewpoints