50 free Mount St. Helens trivia questions with answers — geography quiz, new questions added Aug 2026.
This Mount St. Helens trivia quiz covers the Cascade volcano whose 1980 eruption remains the most economically destructive volcanic event in American history. The easy questions cover the state, the year, the death toll and the mountain's Fujiyama-like shape before the blast. From there the quiz moves through the eruption itself: the March earthquake, the bulge on the north face, the 5.1 quake at 8:32 on a Sunday morning, the largest debris avalanche in recorded history, the lateral blast, the ash that reached Edmonton and the 1,300 feet the summit lost. The hard end covers the Kalama and Goat Rocks eruptive periods, the 1831 ash that tinted the sun over Nat Turner's Virginia, George Vancouver's diplomat friend, the Klickitat legend of Loowit and the Bridge of the Gods, Harry R. Truman, David Johnston's last radio call, Robert Landsburg's camera, the Crater Glacier that grew inside the breach, the whaleback and the slab of the 2004-2008 eruption, and the returning mountain goats and beavers. Every answer was checked against the encyclopaedia entry on Mount St. Helens before publishing and the supporting sentence is stored with each question. Our volcanoes and national parks quizzes are natural next stops.
30 of 50 questions with answers and explanations. Play the quiz
Q 01In which US state is Mount St. Helens?
Washington
It sits in Skamania County, about 52 miles north-east of Portland and 98 miles south of Seattle.
Q 02On which day of the week did the 1980 eruption happen, sparing loggers from the blast zone?
Sunday
Had it come a day later, the death toll could have been much higher.
Q 03How many people were killed by the 1980 eruption?
57
Because it happened on a weekend, loggers were not at work in the blast zone; the toll could otherwise have been far higher.
Q 04What was the magnitude of the earthquake that triggered the collapse of the mountain's north face?
5.1
It struck at 8:32 am and set off the largest debris avalanche in recorded history.
Q 05By roughly how much did the eruption reduce the height of the summit?
About 1,300 feet
The peak went from 9,677 to 8,363 feet, leaving a crater open to the north.
Q 06What shape is the crater left by the 1980 eruption?
Horseshoe
It is about a mile wide with its north end open in a huge breach.
Q 07What rating did the 1980 eruption receive on the Volcanic Explosivity Index?
5
It was classed as a Plinian eruption and released more than 1.5 million tonnes of sulphur dioxide.
Q 08How high did the ash plume rise on 18 May 1980?
12 to 16 miles
It erupted vigorously for more than nine hours and moved east at about 60 mph, reaching Idaho by noon.
Q 09In which Canadian city was ash from the eruption found on cars and roofs the next morning?
Edmonton
Downwind farms in the eastern part of the state suffered about $100 million of damage.
Q 10What is the term for the volcanic mudflows that raced down the Toutle and Cowlitz rivers?
Lahars
They carried nearly four million cubic yards of material 17 miles into the Columbia River.
Q 11Over roughly what area did the pyroclastic flow flatten vegetation and buildings?
230 square miles
Nearly 7,000 big-game animals and an estimated 12 million hatchery fish died.
Q 12What was the name of the 83-year-old lodge owner who refused to evacuate and died in the eruption?
Harry R. Truman
He had lived by Spirit Lake since 1929; his body was never found.
Q 13What were volcanologist David Johnston's last radioed words from Coldwater Ridge?
"Vancouver! Vancouver! This is it!"
He was 30; the observatory on the ridge now bears his name.
Q 21What nickname did the symmetrical, snow-covered pre-1980 cone earn?
Fujiyama of America
Before the eruption it was the fifth-highest peak in its state.
Q 22How many named glaciers covered the mountain just before the 1980 eruption?
11
Only the Shoestring Glacier revived somewhat afterwards, but a brand-new Crater Glacier grew inside the breach.
Q 23What is unusual about the Crater Glacier that formed after the eruption?
Its volume equals all the old glaciers combined
Shaded by the crater walls, it grew about 14 feet thicker per year and now surrounds the lava domes.
Q 14How did photographer Robert Landsburg preserve his pictures of the approaching ash cloud?
He lay on top of his backpack to shield the film
His body and camera were found on 4 June 1980, and the photos gave geologists valuable documentation.
Q 15Which US president compared the devastation unfavourably with the surface of the moon?
Jimmy Carter
He said the moon 'looks more like a golf course compared to what's up there'.
Q 16What happened to the compasses of the film crew dropped on the mountain on 23 May 1980?
They spun in circles
Lost, the crew survived a second eruption on 25 May and was rescued by National Guard helicopters two days later.
Q 17What artificial gemstone is made from Mount St. Helens ash?
Helenite
The ash was also used for ceramic glazes and sold as a tourist curio.
Q 18After whom did George Vancouver name the mountain in 1792?
A British diplomat, Baron St Helens
Alleyne FitzHerbert was a friend of the explorer, who named it as HMS Discovery entered the Columbia's mouth.
Q 19What is the Klickitat name for the mountain, meaning 'smoking or fire mountain'?
Louwala-Clough
In their legend the maiden Loowit became the volcano after two rival chiefs fought over her.
Q 20In the Bridge of the Gods legend, which mountain did the proud suitor Wy'east become?
Mount Hood
His rival Pahto, head bowed toward his fallen love, became the sister mountain to the east.
Q 24Mount St. Helens is one segment of which larger geological feature that rings the Pacific?
The Ring of Fire
It sits in the Cascade Volcanic Arc, fed by an oceanic plate subducting beneath North America.
Q 25How old is Mount St. Helens, making it geologically young among the Cascade volcanoes?
Under 40,000 years
The summit cone that existed before 1980 began rising only about 2,200 years ago.
Q 26Which Cascade peak, 34 miles to the east, is considered Mount St. Helens's 'brother'?
Adams
Both lie about 50 miles from Mount Rainier, the highest of the Cascades.
Q 27Which eruptive period, from around 1480, saw the volcano reach its greatest height?
Kalama
Its opening eruption was several times larger than that of 1980; the period ended around 1647.
Q 28The 57-year eruptive period that began in 1800 is named after which feature?
The Goat Rocks dome
It is the first period for which both oral and written records exist.
Q 29An 1831 eruption tinted the sun bluish-green over Virginia. Who took it as a sign to act?
Nat Turner
He interpreted the strange sun of 13 August as the final signal for his rebellion.
Q 30In 1829 Hall J. Kelley campaigned to rename the entire Cascade chain as what?
The President's Range
Each major peak would have taken a president's name; St. Helens was down for the first one.