Sourdough Rock Glacier, Wrangell Mountains Alaska. The Sourdough is one of the most dramatic rock glaciers around the world. The geomorphology of rock glaciers would be an excellent topic for a research paper for this class. This photograph was taken by Sarah Skelly ('99). Sarah studied a nearby glacier for her IS. Ryan McAllister ('00) studied a nearby sand dune for his IS. A future IS would be the dendrogeomorphology of this rock glacier, interested?