Global Volcanism Program | Image GVP-03191
Wizard Island is a scoria cone in Crater Lake caldera, which formed about 7,700 years ago. A lava flow from a vent on its NW flank forms the peninsula to the left. Llao Rock, a massive lava flow that forms the peak on the caldera rim, was erupted about 100-200 years prior to formation of Crater Lake caldera.
Photo by Dave Wieprecht, 1995 (U.S. Geological Survey).