Academic journal article Oregon Historical Quarterly

The Evolving Landscape of the Columbia River Gorge: Lewis and Clark and Cataclysms on the Columbia

Academic journal article Oregon Historical Quarterly

The Evolving Landscape of the Columbia River Gorge: Lewis and Clark and Cataclysms on the Columbia

Article excerpt

RAVELERS RETRACING 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, timber harvest, altered fisheries, transportation infrastructure, and growth and shrinkage of communities have transformed the river and valley. (1) 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 chroniclers and present-day critics of the modern condition--an ecotopia 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; but the geologic history of immense floods, landslides, and volcanic eruptions that occurred before their journey had equally, if not more, acute effects on landscapes and societies of the gorge. In many ways, the Lewis and Clark Expedition 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 changes geologically engendered in the thousands of years before.

In their landscape and hydrographic descriptions, Lewis and Clark recorded effects of several different "cataclysms on the Columbia," a phrase John Allen used for the title of his 1986 book on the ice-age Missoula floods. (2) Geologic cataclysms affecting the Columbia River Gorge, however, include more than the gigantic floods of fifteen to seventeen thousand years ago. Others involve more human timescales. In addition to shooting through the narrows at The Dalles of the Columbia, perhaps a remnant of the great ice-age floods, Lewis and Clark drifted past a submerged forest and portaged Cascade Rapids, the result of a huge landslide only three hundred and fifty years before their exploration. At the downstream end of the gorge, Lewis and Clark walked on rich bottomlands partly formed by Mount Hood volcanism fewer than twenty-five years earlier. This essay aims to weave Lewis and Clark's first maps and observations of these three areas into a narrative of modern geologic thinking about landscape formation, particularly for the Columbia River Gorge.

"Other objects worthy of notice will be the soil & face of the country ..."

WHILE NOT TRAINED AS GEOLOGISTS, Lewis and Clark, true to Jefferson's instructions, were careful observers of the landscape. (3) They provided volumes of rich observations and findings that established both geographic knowledge and methodological precedent for future explorations and surveys of the West. In the spring of 1804, however, when Lewis and Clark headed west, geology was hardly an established science. The first widely distributed scientific treatment of earth history had been published in 1802, John Playfair's Illustrations of the Huttonian Theory of the Earth. This treatise advanced the emerging British idea that the earth's features were formed by slow, continuous processes, not by radical upheavals such as biblical floods. This concept of uniformantarianism and the effectiveness of slow gradual erosion by rivers were advanced more fully by Charles Lyell in his 1830-1833 Principles of Geology. (4)

Many surveys of the Columbia River region after Lewis and Clark would include geologists: James D. Dana of the U.S. Exploring Expedition of 1838-1842; John S. Newberry of the Pacific Railroad Surveys of 1854-1855; Samuel F. Emmons of the King Survey of 1867-1873. In 1879, Clarence King's survey of the fortieth parallel and three other western geological and topographical surveys merged into the U.S. Geological Survey (USGS), with King as director. Within the newly formed USGS were Emmons, John Wesley Powell, Clarence E. Dutton, and proteges of Newberry such as G. …

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