During the 18th century, Native American villages occupied the mouths of nearly every stream along this coastline, including at Siletz Bay. Oral traditions of many Pacific Northwest coastal tribes record great flooding and ground shaking events and include instructions for preparing for large floods. On January 26, 1700, a magnitude 9+ earthquake along the offshore Cascadia Subduction Zone shook the earth violently. From northern California to British Columbia, the ocean floor rose about 20 feet, and within 10 to 20 minutes a giant wave 30 to 40 feet high reached the shore. The wave probably struck this beach 22 minutes after the earthquake and fully inundated the coast in about 30 to 35 minutes. Devastating waves continued to strike the entire coastline for several hours, flooding beaches, bays, tidal channels, and marshes. Geologic records show that major earthquakes and tsunamis occur along this part of the Pacific coast every 100 to 1000 years, averaging about every 500 years.