<P> The Klamath Native Americans of the area thought that the mountain was inhabited by Llao, their god of the underworld . After the mountain destroyed itself the Klamaths recounted the events as a great battle between Llao and his rival Skell, their sky god . </P> <P> The 1700 Cascadia earthquake resulted from a rupture at the Cascadia subduction zone along the coast of the Pacific Northwest . The earthquake caused a tsunami that was destructive in Japan; it may also be linked to the Bonneville Slide, in which a large part of Washington's Table Mountain collapsed into the Columbia River Gorge, damming the river and forming the Bridge of the Gods, a land bridge remembered in the oral history of local Native Americans . </P> <P> Celilo Falls, a series of rapids on the Columbia River just upstream of present - day The Dalles, Oregon, was a fishing site for natives for several millennia . Native people traveled to Celilo Village from all over the Pacific Northwest and beyond to trade . The rapids were submerged in 1957 with the construction of The Dalles Dam . </P> <P> In 1980, Mount St. Helens in nearby Washington erupted violently, temporarily reducing the Columbia River's depth to as little as 13 feet, and disrupting Portland's economy . The eruption deposited ash as far into Oregon as Bend . </P>

Where did the majority of oregon's permanent settlers come from