I sometimes wonder what it was like for the Spanish explorers when they first glimpsed the Grand Canyon. I can see them staggering through the forest, their heads bent, their heavy feet threatening to give way with every step. Suddenly they are standing on red rock. Too tired to care, they lean their heads back to pour a douse of water into their mouths, then choke as they see what lies before them; a deep canyon of painted rock stretching for miles and miles, the men’s f...