Bonneville Dam

On a “cloudy dark and disagreeable” 30 October 1805, the Corps “passed Several places where the rocks . . . have the appearance of haveing Separated from the mountains and fallen promiscuisly into the river.” Dead tree stumps stood in the water, giving it, Clark said, “every appearance of the rivers being damed up below from Some cause which I am not at this time acquainted with.” In fact, about A.D. 1250 a mountainside slid into the gorge from the north, damming the river. Eventually the river broke through and spilled over a forty-five-foot-high staircase of rubble some four miles long, creating the Cascades of the Columbia at the west end of the Columbia Gorge.

That evening the Corps camped in the vicinity of today’s Stevenson, Washington, around the big bend in the distance. They spent the next day scouting the river and found the obstacle Clark had anticipated—a half-mile-long chute 150 paces wide, “water passing with great velocity forming [foaming] & boiling in a most horriable manner.”

On 1 November 1805, the men hauled their baggage in the rain for 940 yards around the chute, struggling along slippery riverbanks and through swarms of fleas and lice. The next day they left the river’s last natural impediment behind them. With 146 miles of “Smoth gentle Stream” ahead, the worst that was left to endure was the weather.

The Bonneville Dam, completed in 1938, raised the level of this part of the Columbia seventy-two feet and permanently obliterated the place Lewis and Clark called the “Great Shute.”

From Discovering Lewis & Clark from the Air
Photography by Jim Wark
Text by Joseph Mussulman
Reproduced by permission of Mountain Press