Mount St. Helens is a stratovolcano located in the Pacific Northwest region of the United States, in Washington State. It is part of the Cascade Range and stands at an elevation of 8,363 feet (2,549 meters).

On May 18, 1980, Mount St. Helens erupted in a catastrophic event that resulted in the largest landslide in recorded history, followed by an explosive eruption that devastated the surrounding area. The blast destroyed the volcano's summit, reducing the height of the mountain by about 1,300 feet (396 meters) and releasing a massive plume of ash, gases, and debris that spread over an area of more than 230 square miles (596 square kilometers). The eruption caused 57 deaths and billions of dollars in damages.

Today, Mount St. Helens is an active volcano that is closely monitored by scientists and park rangers. It is a popular destination for visitors who come to see the volcano's unique features, such as the crater, lava dome, and blast zone. The area around the volcano has also undergone a remarkable recovery, with new growth and wildlife returning to the devastated landscape. The Mount St. Helens National Volcanic Monument was established in 1982 to protect the volcano and its surrounding area, and to provide education and recreation opportunities for visitors.