This park encompasses the Crater Lake caldera, which rests in the remains of a destroyed volcano (eventually named Mount Mazama) and the surrounding forestland and hills. This is the only National Park in Oregon.
The lake is 1949 ft (7887323.2 m2) deep at its deepest point, which makes it the deepest lake in the United States, the second deepest in North America and the ninth deepest in the world. However, when comparing its average depth of 1148 ft (349.9 m) to the average depth of other deep lakes, Crater Lake becomes the deepest in the Western Hemisphere and the third deepest in the world. The impressive average depth of this volcanic lake is due to the nearly symmetrical 4000 ft (1219.2 m) deep caldera formed 7,700 years ago during the violent climactic eruptions and subsequent collapse of Mt. Mazama and the relatively moist climate that is typical of the crest of the Cascade Mountains.
The caldera rim ranges in elevation from 7000 to 8000 ft (2133.6 to 2438.4 ). The United States Geological Survey benchmarked elevation of the lake surface itself is 6178 ft (1883.1 m). This National Park encompasses 183225 acre (741.5 km2). Crater Lake has no streams flowing into or out of it. All water that enters the lake is eventually lost from evaporation or subsurface seepage. The lake's water commonly has a striking blue hue, and the lake is re-filled entirely from direct precipitation in the form of snow and rain.