As shown on the History Channel, "How the Earth Was Made: Mount St. Helens" examines the 1980 eruption of Mount St. Helens and the geologic processes that made it the deadliest volcanic event in U.S. history. Using evidence from earthquakes, magma movement, sulfur dioxide emissions, ground deformation, landslides, lateral blasts, ash clouds, and lahars, the video explains how volcanologists reconstructed the eruption and improved volcano hazard prediction. It also explores the Cascade Range, rock dating, ancient deposits, and comparisons to later eruptions such as Montserrat, highlighting how geologists use field data to study Earth systems and natural disasters. The content strongly supports Earth science, geology, U.S. geography, and scientific inquiry curricula. Part of the "How the Earth Was Made" series.