The Park is filled with cirques, hanging valleys and horns; landforms given special names because they were produced by the action of glacier erosion. This erosion that was exerted on the bottoms and sides of the valleys that steered the flow of the glaciers. Glacial erosion results in a change in the valley's cross-sectional shape. Glacial valleys tend to have a pronounced U-shape that contrasts sharply with V-shape valleys created by river erosion. Cirques are the bowl shaped depressions found at the head of glacial valleys. For most alpine glaciers, cirques are the areas in the alpine valleys where snow first accumulated and was modified into glacial ice. Small adjoining feeder valleys entering a large valley in a glaciated mountainous region tend to have their floors elevated some distance above the level of the main valley's floor. This landform is called a “hanging valley”. Hanging valleys develop because large glaciers create more erosion and much deeper valleys. Birdwoman Falls, seen from the Going-to-the-Sun Road, plummets from a hanging valley on Mt. Oberlin. Horns are pyramidal peaks that form when several cirques chisel a mountain from three or more sides. A good example of a “horn” is Mount Reynolds at Logan Pass.
The Park is closed during the winter months