July 27, 1949 Tsunami: Columbia River Valley, WA, United States
A tsunami caused by a landslide began at Columbia River Valley, WA, United States on July 27, 1949 at 18:00 UTC. The water rose as high as 19.81 meters. Its effects were recorded at 1 place.
Where the waves reached
The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.
- Under 1 m
- 1 to 3 m
- 3 to 10 m
- 10 to 30 m
- 30 m and more
- Height not recorded
The tsunami
- Date
- July 27, 1949, 18:00 UTC
- Source
- Columbia River Valley, WA, United States
- Cause
- Landslide
- Maximum water height
- 19.81 m (65.0 ft)
- Runups recorded
- 1
- Tsunami magnitude (Iida)
- 4.3
- Waters
- A lake or river, not the ocean
- How certain
- Definite tsunami
- Source location
- 47.820° N, 118.360° W
The toll
- Damage
- Limited (under about $1 million)
Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.
What the record says
NCEI’s account, from the sources it cites.
A two to three million cubic yard landslide occurred near the mouth of Hawk Creek about 35 miles above the Grand Coulee Dam, Washington. A 65 foot wave destroyed beaches and shrubbery directly across the lake. The wave was observed 20 miles away. Debris came down a slope averaging 30o and 380 feet high. (Reference #237)
Note: location (approximate) and time from reference #1695
Every runup
Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.
| Where | Country | Km from source | Water height, m | Inland, m | Measured by | First wave, UTC | Deaths |
|---|---|---|---|---|---|---|---|
| F.D. Roosevelt Lake, WA, WA | United States | 4 | 19.81 | Eyewitness observation of water height |
More
Every tsunami in 1949The 1900sTsunamis of United StatesThis day in weather historyAlerts in force
Sources
Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 1794.