Crystal Peak is the remnant of a much larger tuff flow from a volcano that erupted about 33 million years ago. It is quite remarkable how it seems to have been plopped directly on top of the much older formations that lie below it; you can see an unconformity all around its base. Many visitors think that this structure would be a national park if it were located in an eastern state. The Mountain’s rhyolite tuff contains many small quartz crystals which can be collected in eroded sand around the base.