red rock canyon national conservation area rock climb

red rock canyon national conservation area mountain nevada climb las vegas usa two pinkish spots climbers colorful hiking clark formation mojave desert sandstone pink people sport tourism tourist sight-seeing adventure ecosystem environment wall slab bouldering scrabbling laramide orogeny Paleozoic Mesozoic tectonic geology geological history recreation climate Keystone oxidation sandstone activity outdoors mountain-building Aztec Moenkopi scenic scenery escarpment