Cascade Locks: Engineering the Columbia

The Columbia River Gorge is one of the most dramatic water corridors in North America, but for most of the nineteenth century it had a problem. Right here, the river dropped through four miles of churning rapids called the Cascade Rapids, impassable to steamboats, requiring every ton of freight and every westbound traveler to be portaged overland around the white water. It was a chokepoint at the heart of Oregon's commerce.

Congress authorized a canal and lock system at the Cascade Rapids in eighteen seventy-six. The Army Corps of Engineers began work two years later. What followed was nearly two decades of difficult labor, with changing engineering plans, unpredictable river conditions, and erratic congressional appropriations that repeatedly halted construction. The project that was supposed to take a few years stretched into a nineteen-year effort.

On November fifth, eighteen ninety-six, the canal and its locks finally opened. The finished structure was ninety feet wide and three thousand feet long, with two locks, one five hundred and twenty-one feet long and the other three hundred and fourteen feet long, that could lift vessels forty-two feet to navigate the height difference. The project cost three million eight hundred thousand dollars. The steamboats that had been fighting the portage for decades now glided through.

The economic impact was immediate. Between eighteen ninety-eight and nineteen twenty, the value of freight passing through the canal exceeded the construction cost in most years. Grain from eastern Oregon and Washington could now move continuously from the wheat fields of the Umatilla Plateau down to Portland and the sea, without any offloading.

The town of Cascade Locks grew up around the canal works. And the place carries one more layer of legend: the natural land bridge that once spanned the Columbia here gave this town and the modern steel bridge its name. Around fourteen hundred fifty A.D., a massive landslide from Table Mountain dammed the river, creating a natural crossing the Native peoples called the Bridge of the Gods. When that natural bridge eventually collapsed, the rocky debris created the very rapids the Army Corps spent nineteen years engineering around. The modern Bridge of the Gods still spans the river here, carrying the Pacific Crest Trail across the gorge.