Crater Lake National Park is in Oregon. It is in the Cascade Mountain Range. Crater Lake is the deepest lake in the United States. It is the seventh deepest lake in the world. It is 1,943 feet deep at its deepest point. It is a pure blue lake. Steep cliffs surround the lake. No rivers flow in or out of the lake. It is filled with melted snow. There are two islands in Crater Lake. They are Wizard Island and Phantom Ship.
Crater Lake has a violent history. A volcano named Mount Mazama formed the lake. It erupted 7,700 years ago. A huge eruption caused the volcano's top to cave in. It formed a volcanic basin. The basin filled with melted snow. This area gets around 45 feet of snow each year! Even though it gets a lot of snow, the lake rarely freezes.