Pyramid Mountain is a subglacial mound located on the Murtle Plateau in Wells Gray Provincial Park, east-central British Columbia, Canada. Pyramid Mountain erupted about 12,000 years ago. It was once mistaken for a cinder cone and is now known to have erupted underneath about 1600 m of glacial ice. The volcano erupted vigorously and cooled rapidly when the hot lava contacted the surrounding ice and melted it, creating an envelope of water around the rising volcano.Wikipedia