Travelers reacting Lewis and Clark's journey to the Pacific over the past two hundred years have witnessed tremendous change to the Columbia River Gorge and its primary feature, the Columbia River. Dams, reservoirs, timer harvest, altered fisheries, transportation infrastructure, and growth and shrinkage of communities have transformed the river and valley. This radically different geography of human use and habitation is commonly contrasted with the sometimes romantic view of a prior time provided both by early nineteenth-century chronicle and present day critics of the modern condition - an ectopia of plentiful and perpetual resources sustaining a stable culture from time immemorial. Reality is more complicated. Certainly the human-caused changes to the Columbia River and the gorge since Lewis and Clark have been profound; by the geologic history of immense floods, landslides, and volcanic eruptions that occurred before the journey had equally, if not more, acute effects on landscapes and societies of the gorge. In many ways, the Lewis and Clark Expidition can be viewed as a hinge point for the Columbia River, the changes engineered to the river and its valley in the two hundred years since their visit mirrored by tremendous cchanges geologically engendered in the thousands of years before.
