This presentation uses data from several eruptive episodes of Mount St. Helens in the 1980's to show the way in which a series of eruptions were accurately predicted by USGS scientists as far as 3 weeks before eruptive activity occurred. Several modules demonstrate the use of earthquakes and deformation of a volcano for predicting eruptions and allow you to predict an actual eruption of Mount St. Helens using data collected by scientists of the USGS Cascades Volcano Observatory.