Boundary Trail in Mount St. Helens National Volcanic Monument, Washington

© Don Geyer/Alam

40 years of recovery. Mount St. Helens National Volcanic Monument, Washington

Today is an important day in American history. We’re standing on the Boundary trail at Johnston Ridge in the Mount St. Helens National Volcanic Monument. Forty years ago today, more than 44,0000 hectares within Gifford Pinchot National Forest was set aside to memorialize the deadliest and most destructive volcanic eruption in the United States. For nearly nine hours on May 18th, 1980, the Mount St. Helens erupted, forever changing the Washington landscape. The volcanic event started at roughly 8:30 on a Sunday morning with a 5.1 magnitude earthquake. This triggered what is known as a ‘lateral eruption,’ which means the lava blast comes out of the side of the volcano, rather than the top. The initial blast shaved more than 300 metres off the mountain’s elevation, resulting in a massive avalanche and the destruction of about 380 square kilometres of the surrounding forest. When the event ended, 57 people had died, 200 homes and almost 300 kilometres of nearby highway had been destroyed.

The monument was established by U.S. President Ronald Reagan in 1982 to preserve the area for research, recreation, and education. The land inside has been left to mostly recover naturally since the eruption. While it’s believed that Mount St. Helens will erupt again sometime within the next few centuries, that has not deterred people from hiking and climbing at the monument, which has been allowed since 1986.