Mount st helens plates involved in its formation

The tectonic plates that are involved in the formation and activity of Mount St Helens are the North American tectonic plate, and the Juan de Fuca tectonic plate.

For millions of years, the Juan de Fuca plate has been subducting bellow the North American plate. Because of this subduction, the surrounding area has started lifting up, creating mountain ranges. One of those mountain ranges are the Cascade Mountains, which are the parent mountain of the St Helens volcano.

This area is known for volcanic activity, falling under the Cascade Arc, and being part of the Pacific Ring of Fire. Because of the rising magma from bellow, numerous volcanoes have formed, and one of them is St Helens. It is a very young volcano, unlike the others, and it has only formed around 40,000 years ago. It is a volcano that has a bad reputation because of the damage it has done in its 1980 eruption, when over 50 people died, and very big material damage was done in the surrounding area.