Crater Lake generates the same questions from almost everyone who sees it, and most have genuinely interesting answers.
How deep is it?
1,943 feet — the deepest lake in the United States and among the deepest in the world. Deep enough that the Empire State Building would be well submerged.
Why is it that blue?
Because of what is not in it. The lake has no inflowing or outflowing rivers, so nothing washes sediment in. It is fed entirely by snowmelt and rain.
The water is therefore exceptionally clear, light penetrates unusually deep, and every wavelength except blue is absorbed on the way. What comes back is that colour.
It is also one of the clearest large bodies of water measured anywhere, with visibility recorded to over a hundred feet.
Is it a volcano?
It is what is left of one. Mount Mazama erupted catastrophically around 7,700 years ago and the summit collapsed into the emptied magma chamber, leaving the caldera. The lake filled it afterwards.
The eruption was witnessed — it appears in Klamath oral tradition, which makes it one of the older events preserved in living memory anywhere.
What is the island?
Wizard Island is a cinder cone that grew after the collapse, so it is a volcano inside a volcano. You can land on it from the boat and walk to the crater at its summit.
Can you swim in it?
Yes, at Cleetwood Cove, which is the only legal access to the shore. The water is cold — it rarely exceeds the high fifties Fahrenheit even in late summer — and the walk back up is steep.
Are there fish?
Yes, and none of them are native. The lake had no fish at all until they were stocked in the late 1800s. Stocking stopped decades ago but two species persist.
How much snow does it get?
An average of over forty feet a year, which is why the rim road is closed for much of it and why late spring visitors find the park still under winter conditions.
When should I go?
July to September for full access. Anything earlier and you are likely looking at a closed rim road and snow-covered trails.
How deep is Crater Lake?
Crater Lake is 1943 feet (592 meters) deep. It is the deepest lake in the United States and the deepest volcanic lake in the world!
