We got to see one and heard two avalanches/glacier calving. We were up on the Cascade Pass trail with a wonderful view of the steep mountains all around us. They claim 300+ glaciers and we had a great view of at least three huge ones. Ice clings to these nearly vertical cliffs and when it lets go it bounces down with a grumble or rumble. It is a very distinct sound that I would hate to hear if I didn’t know exactly where it was coming from. From our vantage though, it was really cool.