Mount St. Helens

Mount St. Helens is an active stratovolcano in Skamania County, Washington, part of the Pacific Northwest in the United States. Known as Lawetlat'la to the local Cowlitz people and Loowit or Louwala-Clough to the Klickitat, it is located 52 miles northeast of Portland, Oregon and 98 miles south of Seattle. The volcano is named after British diplomat Alleyne FitzHerbert, 1st Baron St Helens, a friend of explorer George Vancouver.

The most famous event in its history was the eruption on May 18, 1980, the most economically destructive volcanic event in U.S. history. This eruption caused the deaths of 57 people and destroyed many homes, bridges, railways, and highways. A huge debris avalanche triggered by a magnitude 5.1 earthquake led to a lateral eruption, significantly lowering the mountain's height and creating a large crater.

Even after the 1980 eruption, Mount St. Helens remained active until 2008. Today, it is a popular place for hiking and climbing. In 1982, Congress established the Mount St. Helens National Volcanic Monument to protect the area and help it recover.

Geographic setting and description

Mount St. Helens is located 34 miles (55 km) west of Mount Adams in the western part of the Cascade Range. It is often considered a "brother" mountain to Mount Adams and is about 50 miles (80 km) from Mount Rainier, the tallest mountain in the Cascades. The nearest major volcano in Oregon, Mount Hood, lies 60 miles (100 km) to the southeast.

Geologically, Mount St. Helens is very young compared to other Cascade volcanoes. It formed within the last 40,000 years, and its summit began rising about 2,200 years ago. Before the big eruption in 1980, Mount St. Helens was the fifth-highest peak in Washington and was known for its symmetrical shape and heavy snow cover, earning it the nickname "Fujiyama of America". The mountain's slopes feed three main rivers: the Toutle River to the north and northwest, the Kalama River to the west, and the Lewis River to the south and east. These rivers are filled by plenty of rain and snow.

The area around Mount St. Helens includes parts of Cowlitz County to the west and Lewis County to the north. The nearest community is Cougar, Washington, about 11 miles (18 km) south-southwest of the peak. The mountain is surrounded by the Gifford Pinchot National Forest.

Crater Glacier and other new rock glaciers

Main article: Crater Glacier

After the 1980 eruption, a new glacier formed inside the crater, now called Crater Glacier. It grew quickly, reaching about 0.36 square miles (0.93 km²) by 2004. Over time, new volcanic activity changed the glacier's shape, creating areas where the ice cracked and moved. Even with these changes, the glacier continued to grow, especially on its eastern side. Since 2004, smaller glaciers have also formed on the crater walls above the main glacier.

Climate

Mount St. Helens has an alpine tundra climate (ET).

Geology

See also: Geology of the Pacific Northwest

Mount St. Helens is part of the Cascades Volcanic Province, a band of volcanoes stretching from southwestern British Columbia to Northern California. Deep below this area, an oceanic plate sinks beneath the North American Plate in a process called subduction. As this plate sinks, water escapes and melts parts of the Earth’s mantle. This melted rock, called magma, rises to the surface and creates volcanoes.

The magma collects in two chambers below the volcano. One is 3–7 miles deep, and the other is 7–25 miles deep. The deeper chamber might be shared with nearby Mount Adams and the Indian Heaven volcanic field.

Ancestral stages of eruptive activity

Mount St. Helens began growing 37,600 years ago. Early eruptions created layers of ash and rock. Over time, glaciers reshaped parts of the mountain. Activity paused for thousands of years between eruptions.

Smith Creek and Pine Creek eruptive periods

Around 2500 BC, large eruptions covered wide areas with ash. The biggest eruption happened around 1900 BC, sending ash as far as Mount Rainier National Park and even Banff National Park in Alberta. Later eruptions were smaller but still powerful.

Castle Creek and Sugar Bowl eruptive periods

Around 400 BC, the mountain’s lava changed, and big lava flows covered parts of it. Later, explosive eruptions created fast-moving clouds of ash and rock.

Kalama and Goat Rocks eruptive periods

In about 1480, huge eruptions began again. Ash and rock traveled far from the mountain. Later eruptions built up the mountain’s shape. By 1647, Mount St. Helens had reached its tallest height.

Activity started again in 1800. Ash from these eruptions spread over parts of Washington, Idaho, and Montana. Small eruptions continued until 1857.

Modern eruptive period

1980 to 2001 activity

Main article: 1980 eruption of Mount St. Helens

In 1980, a big eruption changed the mountain. A collapse on the north side caused a huge landslide. Ash shot into the sky and spread far away. Mudflows destroyed bridges and camps. The eruption changed the shape of the mountain and had big effects on the area.

Between 1980 and 1986, new lava formed inside the crater. Small explosions happened often. There were more eruptions in 1989–1990 and 1990–1991.

2004 to 2008 activity

Main article: 2004–2008 volcanic activity of Mount St. Helens

In 2004, new lava began to form inside the crater. Over the next few years, the lava grew and changed shape. Small eruptions sent ash into the air. By 2008, the eruptions had stopped.

Future hazards

Future eruptions could be even bigger than the one in 1980. Mudflows might travel down rivers and affect areas near roads. Scientists watch the volcano closely to keep people safe.

Ecology

Mount St. Helens has special plants and animals. Before a big eruption in 1980, the mountain had thick forests with trees like western hemlock, Douglas fir, and western redcedar. Animals such as Roosevelt elk, black-tailed deer, American black bear, and mountain lion lived there too.

After the eruption, scientists studied how nature came back. Some plants and small animals survived, which helped the forest grow again. Larger animals like mountain goats, elk, deer, and bears were heavily affected but slowly returned to the area. Today, the mountain goat population is growing again, and it is important to the Cowlitz Tribe.

Human history

Importance to indigenous tribes

Native American stories tell of the eruptions of Mount St. Helens and other Cascade volcanoes. The Klickitat people tell a story about the chief of all the gods and his two sons, Pahto and Wy'east. They traveled down the Columbia River and quarreled over a beautiful maiden named Loowit. Their fighting caused great destruction, and the chief of the gods turned the lovers into mountains. Wy'east became Mount Hood, Pahto became Mount Adams, and Loowit became Mount St. Helens, known to the Klickitat as Louwala-Clough, meaning "smoking or fire mountain."

The mountain is also very important to the Cowlitz and Yakama tribes. They consider the area above its tree line to be spiritually significant, and the mountain, which they call "Lawetlat'la" (meaning "the smoker"), is part of their creation story, songs, and rituals. Over 12,000 acres of the mountain have been listed on the National Register of Historic Places because of its cultural importance.

Exploration by Europeans

In 1792, Royal Navy Commander George Vancouver and his crew on the HMS Discovery were the first Europeans to see Mount St. Helens. Vancouver named the mountain after British diplomat Alleyne FitzHerbert, 1st Baron St Helens. Later, reports of an erupting volcano in the area came in, with one eruption happening in 1800.

European colonization and use of the area

The first known report of a volcanic eruption by a non-Indigenous person was in 1835 by Meredith Gairdner, who was working for the Hudson's Bay Company. In 1842, settlers and missionaries saw a big eruption that created ash clouds and small explosions for 15 years. Before 1980, Spirit Lake was a popular place for boating, swimming, camping, and skiing.

Human impact from the 1980 eruption

The eruption in 1980 caused the loss of many lives. If it had happened one day later, when loggers were working, many more people could have been hurt. The eruption also caused damage to farms far away, but it also helped some crops grow better. The ash became a material for making special stones and other products.

Protection and later history

In 1982, President Ronald Reagan and the U.S. Congress created the Mount St. Helens National Volcanic Monument to protect the area. Climbing the mountain was allowed again in 1987 but stopped in 2004 because of new volcanic activity. It reopened to climbers in 2006. Each May, events are held to remember the eruption and discuss safety. In 2023, a mudslide damaged a bridge and affected access to the area.

Climbing and recreation

Mount St. Helens is a popular place for people who like to climb mountains, whether they are beginners or very experienced. Climbers go there all year, but mostly from late spring to early fall. To climb above 4,800 feet on the mountain, climbers need a special permit.

In warmer months, the most common path is the Monitor Ridge Route. It starts at a place called Climbers Bivouac and goes up about 4,600 feet over 5 miles to reach the top. It can be hard work, but it does not need special climbing tools. Most people finish this climb in about 7 to 12 hours.

In winter, many climbers use the Worm Flows Route, which is the most direct way to the top. This route goes up about 5,700 feet over 6 miles. It does not need the special climbing skills needed on some other mountains.

There is also a trail called the Loowit Trail that goes around the mountain at about 4,000 to 4,900 feet. Some parts of this trail, especially near the South Fork Toutle River and Windy Pass, have rules about camping, biking, pets, fires, and going off the trail.

There is a visitor center near the mountain in Silver Lake, Washington, run by Washington State Parks. It has many things to see and learn about the volcano.