Mount Mazama is a volcano in the Oregon segment of the Cascade Volcanic Arc and the Cascade Range located in the United States. The volcano's collapsed caldera holds Crater Lake, and the entire mountain is located within Crater Lake National Park. Its caldera was created by an eruption 42 times greater than the one of Mount St. Helens in 1980.
Mazama's summit was destroyed by a volcanic eruption that occurred around 5677 BC, ± 150 years. The eruption reduced Mazama's approximate 12,000-foot (3,700 m) height by about 1 mile (1,600 m). Much of the volcano fell into the volcano's partially emptied neck and magma chamber. At 8,159 feet (2,487 m), Hillman Peak is now the highest point on the rim.