The eruption of Mount Mazama
A mountain collapsed into itself and became Crater Lake
About 7,700 years ago Oregon's Mount Mazama erupted so much magma that its summit collapsed, losing some 1,200 m of height; the caldera now holds Crater Lake, at 592 m the deepest lake in the US. The Klamath, who already lived here, kept a legend of a battle between the spirit of the underworld and the spirit of the sky.