April 13, 1984 Tsunami: Columbia River Valley, WA, United States

On Aprll 13, 1984, approximately 8 acres of land above elevation 1290 experienced massive movement. Eight hundred feet of hlghway was lost and telephone and powerlines were severed. Deflation of the mass continued for several months. The area adjacent to the south end of the slide may experience further movement indicated by the tension cracks seen above and below elevation 1290. Durlng 1985 and 1986 these tenslon cracks showed signs of minor additional displacement. (reference #14339)

“I had a local resident reach out to me to ask if we knew anything about a tsunami that he remembered happening after a landslide took out the highway when he was a kid living near Keller in the 1980s. As it turns out, he was describing the 1984 event […] the size of the landslide itself makes the likelihood of a tsunami being generated highly plausible and the lack of any infrastructure or developments near that part of the lake (aside from the highway above) means there would have been little opportunity for impacts that people would have documented.” (reference #14340)

State Transportation Secretary Duane Berentson has authorized construction of a $75,000 temporary highway across the face of a landslide that is blocking a portion of state Highway 21. The slide early Friday morning in Ferry County […] buried 800 to 1,000 feet of the highway (reference #14341)