Visit of the Arches National Park this winter (Nov, 2010) made it one of my favorite parks in America. From the brochure, "Water and ice, extreme temperatures, and underground salt movement are responsible for the sculptured rock scenery of Arches National Park - 100 million years of erosion created this land boasting one of world's greatest densities of natural arches". Today new arches are being formed and old ones destroyed. Erosion and weathering work slowly but relentlessly, creating dynamic landforms that gradually change through time. It felt like every rock formation had a story to tell - you can name each with your imagination - the special aura of time, silence, and the scale would overwhelm you.