This hanging valley in Glacier National Park contains a waterfall called Bird Woman Falls. A small glacier flowed out of this valley and joined a larger valley glacier that flowed where Logan Creek is located today. Since this glacier was small, it was unable to erode down into the landscape very far, and a hanging valley is what we see today. The size of a glacier determines how far down into the landscape it can erode; the larger the glacier, the deeper the valley it can erode. Thus, hanging valleys form when small tributary glaciers join larger glaciers. We are looking towards the south in this photo. On the map, north is towards the top. The photo was taken from the camera location on the map. The floor of the hanging valley is relatively flat, and thus the contour lines on the topographic map are more widely spaced than those contours representing the sides of the valley. The close spacing of the contour lines at the edge of the hanging valley indicates a steep drop-off, which is where the waterfall is located.

This hanging valley is located along Milford Sound on the South Island of New Zealand. The water in the foreground is part of Milford Sound, a huge U-shaped valley now flooded with sea water. Glacial troughs that fill with sea water are called fjords. The waterfall comes out of another U-shaped valley where a smaller glacier existed. Because this glacier was smaller than the one that filled Milford Sound, its valley bottom is at a higher elevation than the bottom of Milford Sound, and as a result, today we see a hanging valley.