This picture has been stitched together from 8 individual pictures. The Crater Lake was formed ~ 7700 years ago in the caldera after the eruption and collapse of Mount Mazama. It has the cleanest water in the USA, almost free of suspended particles, it is also very deep, that´s why the color appears as dark blue. The volcanic cone shaped island on the left is Wizard Island (4400 years old), the small islet on the right is named as Phantom Ship island.