Crater Lake National Park Trivia
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48 free Crater Lake National Park trivia questions with answers — geography quiz, new questions added Oct 2026.
This Crater Lake National Park trivia quiz covers Oregon's only national park and the astonishing blue lake that fills the caldera of Mount Mazama. Questions cover the geology (the eruption 7,700 years ago that dropped the mountain a mile, the ash that reached Yellowstone, the cinder cone that became Wizard Island), the numbers (1,949 feet deep, 463 inches of snow a year, water so clear a disc was seen 142 feet down) and the wildlife and forests around the rim. The history includes the Klamath legend of Llao and Skell, the gold prospectors who found 'Deep Blue Lake' in 1853, William Gladstone Steel's 17-year campaign after reading about the lake on a newspaper wrapped round his lunch, the 1886 sounding expedition with piano wire, Theodore Roosevelt's 1902 signature, the lodge that nearly collapsed and the Old Man of the Lake, a hemlock trunk that has bobbed upright since at least 1896. Questions run from easy to expert with the difficulty shown on each one. Every answer was checked against a reference page and each question carries its citation. If you enjoy this one, try our Yellowstone and US National Parks quizzes next.
30 of 48 questions with answers and explanations. Play the quiz
Q 01Crater Lake National Park is in which US state?
Oregon
Oregon. Crater Lake is the state's only national park, and it exists because one man, William Steel, campaigned for 17 years to have the lake protected.
Q 02Crater Lake fills the caldera of which collapsed volcano?
Mount Mazama
Mount Mazama, a stratovolcano in the southern Cascades, grew over hundreds of thousands of years before its summit collapsed into the emptied magma chamber; the Klamath people witnessed the eruption and kept its memory in legend.
Q 03How deep is Crater Lake at its deepest point?
About 1,900 feet
About 1,900 feet. The Park Service gives 1,943 feet and a 2000 sonar survey found 1,949, the deepest of any lake in the United States, because the collapsing volcano left a basin nearly 4,000 feet deep.
Q 04How is Crater Lake refilled, with no streams flowing into it?
Entirely by rain and snow falling on it
Entirely by rain and snow falling on it, the lake is kept at a nearly constant level because evaporation and seepage balance the precipitation; with no streams carrying in sediment, it is among the clearest lakes on Earth.
Q 05Roughly how long ago did the eruption and collapse that created Crater Lake's caldera take place?
About 7,700 years ago
About 7,700 years ago (around 5700 BC) the volcano's climactic eruption emptied its magma chamber and the summit collapsed; ash from the blast forms a dated marker layer across the Pacific Northwest.
Q 06How does the US Geological Survey rate the threat posed by the volcano beneath Crater Lake?
Very high
Very high. The volcano is dormant rather than dead: warm fluids still seep from the lake floor, and geologists consider further, smaller eruptions likely.
Q 07After the collapse, about how long did Crater Lake take to fill to today's level?
About 500 years
About 500 years. A US Geological Survey model puts the filling at 420 to 740 years, the longer figure if the climate was drier, and the level has barely moved since, because seepage and evaporation carry off as much water as arrives.
Q 08The volcanoes of the Cascades are fed by the subduction of which piece of oceanic crust?
Juan de Fuca Plate
Juan de Fuca Plate. This small remnant of the once-vast Farallon Plate is still sliding under North America, and when the fault between them slipped in January 1700 the tsunami reached Japan.
Q 09What is Wizard Island?
A cinder cone that rose after the caldera formed
A cinder cone that rose after the caldera formed, Wizard Island began erupting before the lake had filled, so the island visitors see is only the top of a far larger volcano.
Q 10What did William Gladstone Steel name the crater on top of Wizard Island in 1885?
The Witches Cauldron
The Witches Cauldron. Steel named both the island and its summit crater on his first visit to the lake, after paddling across in a canvas-bottomed canoe his party had brought from Portland.
Q 11Why can't visitors see Crater Lake's Merriam Cone?
Its summit is about 500 feet under water
Its summit is about 500 feet under water: Merriam Cone, a volcanic cone on the caldera floor, erupted while the lake was filling, and its smooth, craterless surface shows it was built under water rather than in air.
Q 12Phantom Ship, the small jagged island in Crater Lake, is made of rock roughly how old?
About 400,000 years
About 400,000 years old, Phantom Ship's andesite is the oldest exposed rock in the caldera, a remnant of an early cone; seen in fog or low light the jagged island looks like a ghostly sailing ship.
Q 13What is Crater Lake's 'Old Man of the Lake'?
Q 21About how much snow falls on Crater Lake National Park in an average winter?
About 40 feet
About 40 feet. Recent averages run from roughly 39 to 42 feet, down from about 51 feet in the 1930s, and the drifts that build up keep most of the park's roads closed through late spring.
Q 22Why does Crater Lake rarely freeze over?
Stored summer heat
Stored summer heat. So much water lies beneath so small a surface that only an exceptionally cold winter can ice it over, and the last complete freeze was in 1949.
Q 23Which fish thrive in Crater Lake, which is believed to have had no native fish at all?
Kokanee salmon and rainbow trout
An upright floating log
An upright floating log. The 30-foot hemlock trunk has bobbed vertically around the lake since at least 1896, and it roams: tracked for three months in 1938, it covered more than 60 miles.
Q 14What did scientists use to explore the floor of Crater Lake in the late 1980s?
A one-person submarine
A one-person submarine. Deep Rover carried a single researcher to the bottom on each dive, where it found warm, mineral-rich fluids seeping up through the lake floor.
Q 15What name did the three gold prospectors who came upon Crater Lake in June 1853 give it?
Deep Blue
Deep Blue Lake was their choice, but with gold on settlers' minds the find was soon forgotten, and the lake was renamed at least three times, the last as Crater Lake.
Q 16How did Kansas schoolboy William Steel first learn of Crater Lake?
From a newspaper article wrapped around his lunch
From a newspaper article wrapped around his lunch, Steel read of the lake as a schoolboy in 1870; he did not reach it until 1885, and then spent 17 years lobbying to make it a national park.
Q 17How did the 1886 USGS expedition measure Crater Lake's depth?
A pipe on piano wire from a survey boat
A pipe on piano wire from a survey boat, a half-ton craft hauled up the mountain, gave 168 soundings, and the deepest came remarkably close to the figure sonar produced more than a century later.
Q 18Which president signed the act creating Crater Lake National Park?
Theodore Roosevelt
Theodore Roosevelt signed the bill on 22 May 1902, making Crater Lake the first national park created during his presidency; Steel's lobbying and the 1886 survey data had made the case.
Q 19The climbing club that named Crater Lake's volcano took its own name from which animal?
Mountain goat
Mountain goat. The club took an old word for the animal as its name when it was founded on the summit of Mount Hood in 1894, and it chose William Steel as its first president.
Q 20In Klamath legend, Llao of the Below World battled which chief of the Above World?
Skell
Skell. In the best-known telling his victory destroyed Llao's mountain home, a story that closely parallels what geologists later worked out; Llao Rock and Skell Head on the rim carry the rivals' names.
Kokanee salmon and rainbow trout. Both are outsiders: the lake held no fish until William Steel began stocking it in 1888, and of the species tried over the next half-century only these two took hold.
Q 24What is the only legal way for visitors to reach Crater Lake's shore?
Hiking down the steep Cleetwood Cove Trail
Hiking down the steep Cleetwood Cove Trail, a 1.1-mile path that drops about 700 feet, is the one safe and legal route to the water; it closed in 2026 for a rebuild due to last through the 2028 summer season.
Q 25How were the tour boats on Crater Lake delivered to the water?
By helicopter
By helicopter. No road reaches the shore, so the tour boats had to be flown in, as three new ones were in 2003.
Q 26What is the 33-mile scenic road that circles Crater Lake called?
Rim Drive
Rim Drive. It follows the edge of the caldera all the way round, but the snow lies so deep that the full loop is usually open only from about July to October.
Q 27What is the highest point in Crater Lake National Park?
Mount Scott
Mount Scott is a satellite cone that stood just outside the collapse, so it now rises higher than anything left on the rim, and on a clear day the view from its summit stretches more than 100 miles.
Q 28How do rangers lead winter visitors out across Crater Lake's deep snow to see the lake?
On snowshoes
On snowshoes. The park lends them free for two-hour ranger-led walks that leave the trails behind and wander through the forest and meadows along the rim; no experience is needed.
Q 29What historic structure, built in 1932, stands at the top of the Watchman Peak trail?
A fire lookout tower
A fire lookout tower. It was built to do two jobs at once, watching the forests for smoke and serving as a small trailside museum, on a peak William Steel named during the 1886 survey of the lake.
Q 30Which long-distance hiking route running from Mexico to Canada passes through Crater Lake National Park?
Pacific Crest Trail
Pacific Crest Trail. Crater Lake is one of seven national parks along its 2,650 miles, on a route laid out to avoid towns and keep to high mountain country with few roads.