Nothing demonstrates power to me like a rushing river or a mighty waterfall. Since a glacier is made of mostly ice, there is usually a large amount of water that flows from it. The Herbert Glacier has a very powerful river that rushes from under its belly, down a narrow canyon, and into a wide valley in less than a half mile. As my friend Debbie and I ate lunch, we sat and listened to the roar of the river and admired the force of its flow.