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= Columbia River Littoral Cell = The Columbia River Littoral Cell (also refered as CRLC) is a 165-km long littoral cell on the West coast of the USA located at the mouth of the Columbia River, which separates Oregon and Washington states.

Geography
The Columbia River Littoral Cell (CRLC) is located along the West coast of the USA, in Oregon and Washington states. It extends from Point Greenville, Washington, at its northernmost limit, to Tillamook Point, Oregon, at its southernmost limit. The CRLC consists of four mostly sandy subcells (from north to south): North Beach, Grayland Plains, Long Beach, and Clatsop Plains. The CRLC surrounds the mouth of the Columbia River, which is responsible for the largest water-discharge volume on the U.S. West Coast. It ends the Columbia River drainage basin.

Wave activity
The littoral cell is characterized by a high-energy wave climate with deep-water significant wave heights and periods having annual averages exceeding 2 m and 10 s, respectively, and a mesotidal range of 2-4 m. The littoral cell is significantly impacted during large El Niño-Southern Oscillation (ENSO) events, which took place in 1982-1983, 1997-1998, and 2015-2016. Under El Niño conditions, the wave activity is significantly intensified, especially during winter, with some storm events leading to the most extreme wave and shoreline erosion events on record. For example, in February 1998, average winter wave heights were 2 m larger than the average seasonal conditions along the CRLC. This increase in wave heights introduces more variations in the water levels at the coast, leading to coastal erosion of beaches and dunes.

Geomorphology
Beaches along the CRLC are relatively flat, where beach slopes vary in the range of 0.01-0.05 m/m. These beaches are mostly covered with sand (less than 10% of silt and finer sediment) with a mean grain size of around 0.2 mm on the mid-beach but a huge variance along the CRLC. For instance, the sand on the mid-beach of the northern Grayland Plains subcell has a diameter that varies between 0.6 and 0.7 mm. Sand along the CRLC turns dark once it gets wet, and the beach is usually darker close to the waterline due to the mineralogy, mild slopes, high wave activity, and the large tide range. The sand gradually turns lighter as the waterline gets further from the shore during the tidal cycle. There is also an abrupt transition in the sand color associated with the wet and dry portions of the beach, which often makes the instantaneous shoreline hard to locate between the instantaneous waterline and the wet/dry sand interface. Note that the flatness of the beaches greatly amplifies this effect, where small variations in instantaneous water level induce large variations in the position of the instantaneous shoreline.