The cliffs are composed of volcanic rock but the name is misleading. Eruptions that took place 28 million years ago erupted eight miles to the west (area now known as Never Summer Mountains) depositing ash. Glacial ice carved into the region much later. I'm not sure if I have a photo that will show the tuff talked about in the cross section but you can see the glacier. The blue is where all the snow has melted away. Overhead a ranger talking about how one year all the snow melted leaving just the blue of the glaciers. At 12,080 Ft, the Trail Ridge Parkway is nearing the highest point—12,183 FT!!