Since its first discovery by non-indigenous people in the mid-nineteenth century, Yosemite Valley has held a special, even religious, hold on the American conscience because its beauty makes it an incomparable valley and one of the grandest of all special temples of Nature. While Yosemite holds a special grip on the western mind, perceptions about the Valley have evolved over time due to changing politics, migration patterns and environmental concerns as man has become more attuned to his relationship and impact on nature.