The hydrosphere most likely plays the greatest role in shaping the Rocky Mountains. Rivers and Streams cut pathways through the mighty peaks, creating V-shaped valleys. As the temperature cools, mechanical weathering occurs when water within cracks of rocks freezes and expands, breaking the rocks into several pieces. When waterfalls run down the sides of mountains, they weather away the surface as they go. For example, at Alberta Falls, the water slowly erodes away the rock, widening its path. As glaciers, like Taylor Glacier, move through the already existing valleys, widening and deepening them, transforming them into U-shaped valleys called glacier troughs. An example of this is Fall River Canyon.
In addition, glaciers are responsible for a few other features found throughout the park such as cirques (picture at right), where the glaciers originate from, horns, formed when several glaciers form cirques around the same peak, and moraines, layers and ridges formed by deposited debris of glaciers. The hydrosphere has made the most obvious impact on the Rocky Mountains.
