Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States.
Its current elevation is 2,550 meters above sea level, and it is located 154 kilometers south of Seattle, and 85 kilometers northeast of Portland, Oregon. The mountain is part of the Cascade Range and was known as Louwala-Clough, which means “smoking or fiery mountain” in the language of the local indigenous tribe of the Klickitats.
Its current name was given after British diplomat Alleyne Fitzherbert, 1st Baron of St. Helens, who was a friend of George Vancouver, a Royal Navy Commander who surveyed the area in the late 18th century. St. Helens is well known for its ash explosions and pyroclastic flows.
Like most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits.