Crater Lake is a crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The lake partly fills a nearly 2,148-foot-deep caldera that was formed around 7,700 years ago
by the collapse of the volcano Mount Mazama. There are no rivers flowing into or out of the lake; the evaporation is compensated for by rain and snowfall at a rate such that the total amount of water is replaced every 250 years. With a depth of 1,949 feet, the lake is the deepest in the United States. In the world, it ranks ninth for maximum depth, and third for mean depth.
Crater Lake features two small islands. Wizard Island, located near the western shore of the lake, is a cinder cone approximately 316 acres in size. Phantom Ship, a natural rock pillar, is located near the southern shore.
Since 2002, one of Oregon's regular-issue license plate designs has featured Crater Lake and a one-time plate surcharge is used to support the operation of Crater Lake National Park.