At 1,943 feet deep, Crater Lake is the deepest* lake in the United States and the principal feature of Crater Lake National Park.
Approximately 7,700 years ago, Mount Mazama, a stratovolcano with a summit estimated at 12,000 feet, violently erupted in one of the most explosive geological events in human history. During the eruption, roughly 14 cubic miles of debris were discharged into the atmosphere and the surrounding landscape, and enough of the volcano's magma chamber was emptied that the remnants of the mountain collapsed, opening an enormous crater over 5 miles in diameter and nearly 4,000 feet deep. Ash from the eruption is estimated to have been 150 times the quantity created by the 1980 explosion of Mount St. Helens, and it landed as far east as Wyoming and as far north as British Columbia. 200 to 300 feet of ash settled at Mazama's base.
Years of heavy precipitation and snowfall filled the crater and eventually formed the deep blue** lake we see today. With no external sources or outlets, Crater Lake maintains a relatively stable surface level as yearly precipitation is balanced with evaporation and ground seepage.
The legend of the massive volcano and the cataclysmic eruption was always well known to Native Americans. In 1853 the lake was first discovered by settlers (gold prospectors), but little attention was given to the lake due to its remote location. The fate of the area forever changed, however, when William Gladstone Steel first visited the lake in 1885. After 17 years of lobbying, the lake, the imploded volcano, and the surrounding area were eventually protected and recognized in 1902 as the country’s fifth national park.
Today, Crater Lake National Park still stands as Oregon’s only national park. Key attractions include:
Designated camping in the park is extremely limited, particularly during summer break and given the closure of Lost Creek Campground. Mazama Village Campground is currently the park’s only operating campground.
Backcountry campsites are available at Lightning Springs (0.8 mile hike in) and along the Pacific Crest Trail, but a special overnight permit which can be obtained at the park headquarters is required.
Lodging is available at Crater Lake National Park mid-May to mid-October, with specific opening and closure dates depending on snowpack. Crater Lake Lodge features 71 rooms, and the Mazama Village Campground has 40 guestrooms in cabins.
Rim Drive and the park’s northern entrance are only open seasonally, typically mid-June to mid-October, due to extensive snowpack. Winter access to the park and rim are only possible via OR Hwy 62, the park's southern entrance. Both of the campgrounds and all lodging is closed during the winter.
* Crater Lake is the ninth deepest lake in the world (Russia's Lake Baikal is the deepest at 5,387 feet), and the second deepest in North America (Canada's Great Slave Lake, 2,014 feet, is first). In terms of average depth, however, Crater Lake's 1,148 feet makes it the deepest lake in the Western Hemisphere and the third deepest in the world.
** One of the mesmerizing aspects of Crater Lake is its astonishingly deep blue color. More than any other lake in the U.S., the lake's clarity and depth capture all other wavelengths of light on the color spectrum, while blue is scattered and reflected back to the human eye.
Dogs on-leash are permitted within the park but only within developed areas and within Mazama Village and Lost Creek Campground. Dogs are not permitted on any trails or in undeveloped areas.