Throughout the West, the phenomenon of "red rocks" are part of the fascinating landscape. These are generally sedimentary rocks, laid down by long-vanished seas. Where the former sea bed has been exposed to air by upthrusting and erosion, rocks containing iron ore have oxidized (we'd call it "rust" if it happened to metal objects) and created the red and orange rock layers. In the warm light of sunrise and sunset, the red rocks take on their warmest colors.