About 7,700 years ago the volcano Mount Mazama erupted and its top fell in. That left a giant bowl called a caldera, which slowly filled with water.
Photo: Glenn Scofield Williams / Wikimedia Commons (CC BY 2.0)
No rivers flow into Crater Lake. It fills with only rain and snow, so the deep, clean water shines a strong blue.
Photo: David Weekly / Wikimedia Commons (CC BY 2.0)
Wizard Island is a small volcano that grew inside the lake. Its cone rises about 760 feet above the water.
Photo: Ken Lund / Wikimedia Commons (CC BY-SA 2.0)
Tough trees like the whitebark pine grow along the windy rim. They can live for hundreds of years in the thin, cold mountain air.
Photo: Oregon Department of Fish and Wildlife / Nick Myatt / Wikimedia Commons (CC BY-SA 2.0)
Clark's nutcracker is a gray and black bird. It hides thousands of pine seeds in the ground, and the seeds it forgets grow into new trees.
Photo: Edward S. Curtis, 1923 / Wikimedia Commons (public domain)
The Klamath people have lived near this lake for thousands of years. They call it giiwas, which means a sacred place, and their families saw Mount Mazama erupt long ago.
A road called Rim Drive circles the whole lake. It runs about 33 miles around the top of the caldera, so you can see the water from many sides.
Photo: Scott Catron / Wikimedia Commons (CC BY-SA 3.0)
Crater Lake Lodge sits right on the edge of the rim. It first opened to guests in 1915, and people have stayed there to watch the lake for more than a hundred years.
Photo: cricketsblog / Wikimedia Commons (CC BY 2.0)
The golden-mantled ground squirrel lives at the park. It has a striped back and a golden head, and it stuffs seeds into its cheeks to carry them home.