Crater Lake National Park Travel Guide. Crater Lake National Park in southern Oregon protects one of the deepest and clearest lakes on Earth. Formed nearly 7,700 years ago after the collapse of Mount Mazama, the lake fills a massive volcanic caldera with water of astonishing depth and color.

The morning fog hovered over the rim of Crater Lake , veiling its secrets. As the sun tiptoed through the clouds, the lake emerged, a...