"But look again! These terrifying walls are moving, are changing. A new light is not only creeping over them, but is coming out from their very shadows. See these flattened slopes above the dark sandstone on top of granite, even at this very moment they are being colored in gorgeous stripes of horizontal layers of yellow, brown, white, green, purple. What means this wondrous change? Wherein lies the secret of the great canyon?"
Robert B. Stanton