Washington's Coast
Washington State Department of Ecology



Wide sand beach, Ocean Shores

Along Washington's southwest coast, wide sand beaches stretch from the mouth of the Columbia River to Point Grenville.

Columbia River sand
built these beaches

For the past five thousand years, the Columbia River has carried sand to the coast. Currents, waves and wind have swept sand north and south -- from the Columbia River mouth to build up dunes and beaches. Millions of cubic yards of Columbia River sand are stored in these linear dunes and beaches, also called barriers. The Columbia River supplies sand to 100 miles of beaches, from Oregon's Tillamook Head to Washington's Point Grenville. As sand moves north up Washington's coast, the amount available to nourish beaches decreases. At Point Grenville, the trailing end of Columbia River sand is deposited. North of Point Grenville, the contribution of Columbia River sand to beaches is small.
Sand deposited along barriers and beaches
Long Beach sand and developing foredune Sand for miles
The Long Beach peninsula, a huge spit, was formed by sediments delivered to sea by the Columbia River. Waves and currents slowly reworked the sediments to build the 19 mile long peninsula which is only about a mile wide. Broad sand beaches front an upland sand plain, laced with parallel dune ridges, bogs, lakes, and woodlands.
Wind sculpted current ripples, Fort Canby State Park What's in the sand?
Beach sand from the Columbia River is made of light minerals, lithic fragments, and heavy minerals such as: hornblende, augite, hypersthene, magnetite. Some minerals come from mountains many miles away -- as far as the Rockies. These mountain minerals brought to sea nourish beaches and intertidal life such as razor clams.
Erosion hits close to condominums, Ocean Shores Sand loss
Within the last century, the flow of sand from the Columbia River has been altered by dams, jetties, and other development. Erosion hot spots have developed along Washington's southwest coast.
Images courtesy of: Greg Pelletier, Brian Voigt; S. Eykelhoff, R.C. Daniels. Coastal surface geology of Washington State, 2000. In Coastal and Marine Slide Compilation (CD-ROM), Volume 1. R.C. Daniels (ed.). Coastal and Marine Specialty Group, Association of American Geographers, Washington D.C. To order this publication, visit http://aag_coma.homestead.com

Southwest Washington Coastal Erosion Study. A recent study of coastal processes and shoreline changes within the Columbia River littoral cell.
"Shoreline Aerial Photos, Washington State Department of Ecology. Aerial photos of Washington state's entire marine shoreline.

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