Castle Lake Limnological Research Station

The uplift of the Cascade Mountains, northwestern United States, is a result of plate tectonics. The Juan de Fuca oceanic plate collides with the North American continental plate forming a convergent plate boundary, creating a subduction zone. The denser oceanic plate descends under the continental plate, and the oceanic crust heats, melts, and forms magma underneath the earth's surface. The Cascade Mountains are a series of volcanoes ranging from Mt. Lassen (California) in the south up to Meager Mountain (British Columbia) in the north.