Loowit Falls is one of two major waterfalls that occurs along the so-called "Sasquatch Steps" on the north flank of Mount St. Helens. When the mountain erupted in 1980, it basically created a catchment basin in the resulting crater. Beginning in the winter of 1980-1981 the Crater Glacier began to form and is currently the largest glacier on Mount St. Helens, as well as the youngest and fastest growing glacier in the United States. Once the glacier began growing, it also began melting and its meltwater has channeled largely into what is now Loowit Creek. As Loowit Creek intersects the blasted out north slope of the mountain it carved out the rugged Loowit Canyon, with Loowit Falls found at its head.
Loowit Canyon occured because Loowit Creek washed away and eroded material that was either pulverized by the 1980 eruption or was unstable enough due to the erution that as the creek cut down it caused massive landslides. Loowit Canyon formed in a matter of about 15 years and over that time Loowit Falls has constantly evolved in appearance. When we surveyed the falls in 2011 it stood 186 feet tall. Imagery available in Google Earth shows the brink of Loowit Falls has retreated upstream by 40 feet since 1994. Some time between 2006 and 2009 a smaller but significant lower tier of the falls was buried almost entirely by a landslide and over the years there has been an increase in rockfall debris collecting at the base of Loowit Falls. What this all means is Loowit Canyon is incredibly unstable and the height and appearance of the falls will most likely continue to evolve in the coming decades.
Geologically Loowit Falls may only exist for a fraction of time so minute it barely registers when looking at the big picture. The falls haven't existed for more than 30 years and with the rapid advance of the Crater Glacier there is a possibility that the stream may either be diverted or the glacier may even cover the falls and spill into Loowit Canyon at some point (the toe of the glacier is less than a mile upstream now).
