Daily Earth Science Geosphere Repost

Bridge of the Gods

We landed at PDX several weeks ago as our family transitioned to a new home in Portland. Our furniture and other household goods were passing through the Panama Canal on a leisurely journey to the Pacific Ocean, and then up the west coast to Portland. We were camping in our new abode awaiting our worldly possessions, but keen to explore the Pacific Northwest. One evening I plotted a day trip up the Columbia River Gorge with plans to make a crossover to the Washington side at Cascade Locks. The map informed me we would exit I-84 East and then cross the river on the Bridge of the Gods to reach SR 14 on the Washington side. What an exotic name, I thought, “Bridge of the Gods.” 

The next day we arrived at the river crossing and were met by a quaint bridge with open-grid steel decking suspended in a steel girder framework. We paid a couple of dollars to cross, and I commented to my wife the structure was nice, but “Bridge of the Gods” was a bit too grandiose a name for the experience. Of course, I missed the point completely. The name referred to the landform the bridge sat upon, and the actual bridge had merely borrowed the name.

Love and jealously (A Klickitat tale)

Hidden in the mists of time is a period when gods ruled the earth, and it was in those days when the powerful god-chieftain Tyhee Saghalie set out upon a journey with his two sons Pahto and Wy’east. They were searching for a land of beauty and bounty where they could settle and thrive. Their wanderings eventually brought them to a river gushing from the north and slicing its way through a range of sparkling snow-capped mountains.

The travelers gazed at the beautiful land, and each of the sons greedily wanted it all for themself. They quarreled for days until Tyhee Saghalie could take no more. He silenced them, and while they watched, he shot two arrows into the clear blue sky. One arrow traveled far into the mountains north of the river, and Pahto followed it. The second arrow sped southward chased by Wy’east.  But Saghalie was distressed that the river separated his sons, so he built a spectacular stone bridge for the brothers cross and reunite occasionally—truly a bridge of the gods

 The young gods were happy until they both fell under the charms of the lovely Loowit. A burning desire for the maiden blinded both sons, and a violent fight erupted. The earth shook under their blows, burying villages and forest, and eventually causing Saghalie’s magnificent bridge to collapse into the river. 

Saghalie’s anger exploded, and his punishment was swift. The three lovers were struck down and turned into mountains where they fell. Loowit was fleeing towards the ocean, and she transformed into Mount St. Helens. Pahto and Wy’east remained on opposite sides of the river. Pahto (Mount Adams) tilted his head westward towards is love, and Wy’east (Mount Hood) gazed northward across the river at his brother and lost love.

Disaster along the riverbanks

Geologists have a vastly different story about the Bridge of the Gods. Over 150 years before the first European settlers set foot at Plymouth Rock or Jamestown, the Pacific Northwest was rocked by a massive earthquake. Current thinking believes seismic energy from this quake initiated the Bonneville landslide. Catastrophic failure along the river-facing, southern sides of Table Mountain and Greenleaf Peak sent rock and debris from the Washington side tumbling into the Columbia River Gorge—damming off the river just north of Bonneville Dam at the town of Cascade Locks.

The rockslide stretched across the Columbia River Gorge, measuring about 3.5 miles long and 200 feet high. River waters pooled behind the rockslide, rising higher for some 35 miles upstream and creating a lake that flooded the forests on either side of the gorge. By the time the first white settlers traversed the continent along the Oregon Trail, the river had breached the natural dam and largely washed it away. The remnants from the landslide and dam formed a four-mile stretch of cascading rapids with a 45-foot elevation drop. 

Lewis and Clark navigated these rapids in 1805 on their epic adventure. Later, Oregon settlers migrating from the east—under the allure of free grants of land taken from the native Americans—used the “river path” for the final leg of their journey. As Oregon grew, the Cascade Rapids formed an impediment to river travel, and in 1896, after 18 years of construction, a set of locks opened, allowing navigation from the base of the rapids to the top. Then, in 1938, the Bonneville Dam’s completion created an upstream lake, permanently submerging the Cascade Rapids. 

Mother nature

The landscape forming Cascade Rapids now rests deep below the waters of the Columbia River. However, the scars from the Bonneville landslide remain visible on the Washington side of the river, serving as a potent reminder of mother nature’s power.

The Pacific Northwest is a region where active geological forces constantly reshape the topography, creating a rugged and beautiful terrain. Volcanoes and mountain belts spring up from active subduction as the North American plate slowly rides up over the oceanic Juan de Fuca plate. Even rivers, like the mighty Columbia, are temporarily stopped in their tracks by geological processes occurring on a scale difficult to imagine. Geology has shaped both the history and legends of this region.


Cascadia Unfolding: Anatomy of a Disaster (Source: ArcheanWeb) –  https://archeanweb.com/2019/12/01/cascadia-unfolding/  Also:


Feature Image: Cascade Rapids before the Bonneville Dam (Modified) – By en:United States Geological SurveyThe original uploader was Pud at English Wikipedia.. Later version(s) were then uploaded by Peteforsyth at en.wikipedia. – http://vulcan.wr.usgs.gov/Imgs/Jpg/Historical/corps-engineers-archives_cascades_rapids.jpgTransferred from en.wikipedia to Commons by Legoktm., Public Domain, https://commons.wikimedia.org/w/index.php?curid=3969206

William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.