Bryce Canyon Amphitheater

The Bryce Amphitheater is the largest of several natural amphitheaters carved into the eastern edge of the Paunsaugunt Plateau within Bryce Canyon National Park, Utah, cut into the soft limestone, siltstone and mudstone of the Claron Formation, laid down roughly 50 to 40 million years ago in ancient lakes. The amphitheater is famous for its dense concentration of hoodoos, tall, thin spires of rock left standing after frost wedging and rainwater dissolution eroded away the surrounding softer rock along vertical joints in the plateau's rim; differing mineral content within the layered Claron rock produces the hoodoos' characteristic banding of pink, orange and white. Because the region undergoes more than 200 freeze-thaw cycles a year, the amphitheater's hoodoos continue to be actively shaped, and the rim is estimated to be retreating at roughly a foot every 50 to 65 years, making it one of the fastest-eroding named formations in North America.