Crater Lake National Park is in southern Oregon as part of the Cascade Mountain range. The lake water is so blue and clear because there is hardly anything else in it – just water. Crater Lake was once an ancient volcano known as Mount Mazama. Its greatest eruption occurred about 7,700 years and today, Crater Lake is the deepest lake in the United States and one of the top ten deepest in the world.
Note: with the snowfall the area receives each year, the roadway (‘Rim Road’) is open for a brief time during the summer, so plan accordingly. The park itself is open year-round.

See more photographs of Crater Lake National Park