Type A stratovolcano, sometimes called a composite volcano, is a tall, conical volcano with many layers (strata) of hardened lava, tephra, and volcanic ash.
How it was made Lava erupting at a point in the Cascadian subduction zone
Where the name come from The modern name Mount St. Helens was given to the volcanic peak located in Washington state in 1792 by British Royal Navy Captain George Vancouver, who was a seafarer and explorer. He named it in honor of a fellow countryman, Alleyne Fitzherbert, who held the title Baron St. Helens and was at the time the British Ambassador to Spain. Vancouver also named three other volcanoes in the Cascades. They were Mounts Baker, Hood, and Rainier, which were all named after British naval officers.