Ever heard of the "Bonneville Slide?"
It sounds like some obscure country line dance, but the real story is more interesting, and it comes with a connection to a curious Native legend that turns out to refer to a real historical event.
The Klickitat People have lived for centuries on both sides of the Columbia River, up into what is now Skamania and Klickitat Counties, Washington, and down into Multnomah and Clackamas Counties, Oregon. They tell the tale of Pahto and Wy'east, the two sons of the chief of all the gods, Tyhee Saghalie. The two young men did not get along, and fought over who would rule over which parcel of land. Their father shot one arrow south and the other north; Pahto was given the lands around where the northern arrow landed, and Wy'east the territory surrounding where the southern arrow fell to the ground. Tyhee Saghalie then shook the Earth and created a great bridge across the Columbia River so the two could visit each other.
But soon trouble broke out again. Pahto and Wy'east both fell in love with the same young woman, the beautiful Loowit, and began to fight, burning villages and destroying forests and crops. Tyhee Saghalie tried to reason with them, but to no avail. In the end he grew angry himself and shook the Earth again, destroying the bridge; the cataclysm created a flood that washed away whole forests. He turned all three into mountains -- Wy'east became Mount Hood, Pahto Mount Adams, and the lovely Loowit Mount Saint Helens. But even in mountain form they never forgot either their anger or their burning love, and all three still rumble and fume to this day.
What is fascinating is that this odd story actually appears to have some basis in fact.
In around 1450 C.E., an earthquake knocked loose about a cubic kilometer of rock, soil, and debris from Table Mountain and Greenleaf Peak. The resulting landslide -- the Bonneville Slide -- roared down the Columbia Gorge, creating a dam and what amounted to a natural bridge something like sixty meters high across one of the biggest rivers in the world.
The dam couldn't last, however. The Columbia River has a huge watershed, and the lake that built up behind the dam eventually overtopped the natural "Bridge of the Gods." The whole thing collapsed -- probably during a second earthquake -- releasing all that pent-up river water in a giant flood. It left behind geological evidence, both in the form of a layer of flood-damaged strata west of the slide, and the remains of drowned forests to the east, where trees had died as the dammed lake rose to fill the gorge.
Despite the reminder we got in 1980 -- with the eruption of Mount Saint Helens -- it's easy to forget how geologically active the Pacific Northwest is. Not only is there the terrifying Cascadia Subduction Zone just offshore (about which I wrote two years ago), the other Cascade volcanoes, from Silverthrone Caldera (British Columbia) in the north to Lassen Peak (California) in the south, are still very much active. Right in the middle is the massive Mount Rainier, visible from Seattle, Tacoma, and Olympia on clear days, which is one of the most potentially destructive volcanoes in the world. Not only is it capable of producing lava and pyroclastic flows, it's capped by huge glaciers that would melt during an eruption and generate the catastrophic mudflows called lahars. The remnants of two historical flows from Rainier -- the Osceola and Electron Lahars -- underlie the towns of Kent, Orting, Enumclaw, Puyallup, Auburn, Buckley, and Sumner, and in some places are twenty to thirty meters deep.
The Earth can be a scary, violent place, but somehow, humans manage to survive even catastrophic natural disasters. And, in the case of the Bridge of the Gods, to incorporate them into our stories and legends. Our determination to live in geologically-active areas is due to two things; volcanic soils tend to be highly fertile, and we have short memories. Fortunately, though, we couple what seems like a foolhardy willingness to take risks with a deep resilience -- allowing us to live in places like the Cascades, which are bountiful, and filled with a perilous beauty.
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