In a history of the Grand Canyon, Stephen Pyne (1998) traced a progression of different aesthetics: indifference among the early Spanish explorers; revulsion at a wasteland among the first potential settlers; incomprehension of a huge depression, when landscape taste had discovered mountains; wonder at its geological history, following the discoveries of John Wesley Powell; the American sublime. Each desert has had a similar history of changing tastes, and each will continue to experience this kind of fundamental change.