Crater Lake National Park - General Park Information

Crater Lake has inspired people for hundreds of years. No place else on earth combines a deep, pure lake, so blue in color; sheer surrounding cliffs, almost two thousand feet high; two picturesque islands; and a violent volcanic past. It is a place of immeasurable beauty, and an outstanding outdoor laboratory and classroom.

Crater Lake is located in Southern Oregon on the crest of the Cascade Mountain range, 100 miles (160 km) east of the Pacific Ocean. It lies inside a caldera, or volcanic basin, created when the 12,000 foot (3,660 meter) high Mount Mazama collapsed 7,700 years ago following a large eruption.

Generous amounts of winter snow, averaging 533 inches (1,354 cm) per year, supply the lake with water. There are no inlets or outlets to the lake. Crater Lake, at 1,943 feet (592 meters) deep, is the seventh deepest lake in the world and the deepest in the United States. Evaporation and seepage prevent the lake from becoming any deeper.

Weather plays a dramatic role at Crater Lake National Park. Winter, especially, shapes the landscape; snow generally begins to accumulate each year in October and doesn't melt in most places until the following June. Summer weather is more predictable, with warm, dry days, blue skies, and cool nights. Nevertheless, there may be days even in August when the lake is completely obscured by clouds and fog. Visitors to Crater Lake National Park should be prepared for any kind of weather, any time of the year.