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Bryce is distinctive due to geological structures called hoodoos, formed by wind, water, and ice erosion of the river and lake bed sedimentary rocks. The red, orange, and white colors of the rocks provide spectacular views for park visitors. Bryce sits at a much higher elevation than nearby Zion National Park. The rim at Bryce varies from 8,000 to 9,000 feet .
At Bryce Canyon water in the form of ice is the most efficient form of erosion for breaking rock into smaller pieces. The Paunsaugunt Plateau receives approximately 100 inches of snowfall a year. It also experiences about 200 days of freeze/ thaw. Which means that everyday a small amount of snow melts and runs into the joints and freezes at night. When water freezes it expands to form an ice wedge in the joint widening the space. As the ice wedge grows by more water leaking into the joint and freezing it will finally break the rock.
This is called frost wedging. Small pebbles and large Volkswagen bus sized boulders commonly fall from the sides of existing hoodoos and the sides of the Paunsaugunt Plateau by frost wedging and gravity. The smaller pieces are washed away by the monsoons and snow melt. Boulders explode into cobble sized pieces when they impact the ground. The resulting debris is then washed down slope by snowmelt, flashfloods and gravity.
