How many of us realize that Crater Lake lies in a belt of volcanic activity which entirely circles the Pacific Ocean? In the far north there are many evidences of volcanic eruption along the Aleutian peninsular of Alaska. This zone curves southward and extends along the western border of North America, South America and then westward across the southern Pacific Ocean. Many of the south sea islands, all of which owe their origin to volcanic eruptions, lie in this belt. The same conditions exist in the East Indies and along the eastern margin of Asia, thus completing the circle. Although the remnant of ancient Mount Mazama is but one of many thousands of volcanic peaks occurring in this zone, it is unique in that nowhere else is there found a lake, nestled in a crater or caldera, which can compare with our own Crater Lake.

Just what causes this great volcanic belt, science does not know. It must represent a zone of weakness in the crust of the earth through which molten rock and gases are able to reach the surface. But how may we explain the location of this relatively weak zone? That is another answered question. Some authorities believe that the weight of the ocean water pressing down on the ocean bottom forces subsurface material to either side, much as a block of wood might do if pressed down into a mass of heavy mud. This action might be expected to push up mountains along the continental margins and force molten rock and gas through the crust of the earth.

We should remember that Crater Lake and Mount Mazama, although magnificent and awesome in themselves, are expressions of some great system of forces which are continually at work in shaping our earth.