Crater Lake, located in southern Oregon, is the deepest lake in the United States and the seventh deepest in the world. Fed by rain and snow, but no rivers or streams, the lake is considered to be the cleanest large body of water in the world. The water is exceptional for its clarity and intense blue color.

The lake rests inside a caldera formed 7,700 years ago when Mount Mazama, a 3,600 meter volcano, collapsed following a major eruption. The eruption may have been the largest in North America in the past 640,000 years. Later eruptions formed Wizard Island, a cinder cone near the southwest shore.