Wyoming

Wyoming is the corridor’s dolomite and limestone heartland, and its best-documented ground: Lander built a town’s identity around Todd Skinner’s Wild Iris, and Ten Sleep Canyon grew from a local secret into an international destination — and into one of American sport climbing’s hardest ethics fights. Come for the pocketed stone; read the access history before you clip a bolt.

Both areas sit on the same arrangement of rock: a Laramide uplift that raised an Archean core and tilted the Paleozoic carbonate section off its flanks into cliffs. Both are climbed on Madison Limestone and Bighorn Dolomite — and at both, climbers call all of it dolomite, which is right about the rock and wrong about the formation. The pages explain the difference, and where those famous pockets actually come from.