Question: What volcanic events formed Crater Lake, OR? When did they take place?
- A powerful explosion blew away the top of a stratovolcano; 10 million years ago.
- The crater of a large, extinct cinder cone filled with water; 5 million years ago.
- Landslides and volcanic mudflows dammed the Mazama River; 500 years ago.
- Caldera collapse followed major ash and pyroclastic-flow eruptions; 6000 years ago.