Portal:Oregon/Selected article/17

Crater Lake National Park is a United States National Park whose primary feature is Crater Lake. It was established on May 22, 1902 as the fifth National Park in the U.S., and is Oregon's only National Park. The park encompasses Crater Lake's caldera, which rests in the remains of a destroyed volcano posthumously called Mount Mazama. About 400,000 years ago, Mazama began life as overlapping shield volcanoes. Over time, alternating layers of lava flows and pyroclastic flows built Mazama until it reached about 11000 feet (3400 m) in height. After a period of dormancy, Mazama became active again. Then, around 5700 BC, Mazama collapsed into itself during a tremendous volcanic eruption. The eruption formed a large caldera that was filled in about 740 years, forming a lake with a deep blue hue, known today as Crater Lake. The lake is 1,949 feet (594 m) deep at its deepest point which makes it the deepest lake in the U.S., the second-deepest in North America, and the ninth-deepest anywhere in the world. The caldera rim ranges in elevation from 7000 to 8000 feet (2100 to 2400 m). The USGS benchmarked elevation of the lake surface itself is 6178 ft (1883 m). The park covers 286 mi² (741 km²) with the highest point at Mount Scott. The lake is filled entirely from direct precipitation in the form of snow and rain.