Travel Guide Mount St. Helens National Volcanic Monument

This young volcano, barely 35,000 years old, has made a lot of headlines in recent decades. After seven weeks of earthquakes and mini-eruptions, on May 18, 1980, an eruption erupted and then shattered its summit, creating a crater 3.2 km long and 1.6 km wide. In ten minutes, a column of smoke and ash rises over 15 km. The sky is veiled by black ashes for hundreds of kilometres around and the cities are covered with soot (up to Spokane). Rocks as big as houses are washed away by rivers of mud. In the spring of 1980, a huge explosion devastated entire forests, leaving piles of trunks on the hills and lakes: 57 people were killed and hundreds of houses destroyed. The mountain, originally 3,000 meters high, lost 450 meters in the eruption. In 1982, Mount St Helens was declared a national monument. Until 1986, a new dome formed in the crater. Then, from now on, the volcano experienced small seismic tremors and smoke releases, the last of which occurred in 2010. The scars of these tectonic whims are still visible today. Roads are being rebuilt on its slopes, scientists are invading the area and analyzing from the volcano's movements. But life has resumed on Mount St. Helens. Trees are growing back near bare tree trunks, and animals have repopulated the devastated area. The mountain is still active. A new eruption is not excluded, even if the geological probabilities are currently low. This eruption provided an opportunity to test new techniques to study the formation of magma in the crater, techniques borrowed from the oil drilling industry and used in particular on Mount Rainier.A large part of the park is not accessible to the public due to geological changes and the need to protect existing ecosystems.