Columbia River Estuary


The Columbia River Estuary is an estuary and a bay on the Oregon-Washington border and the Pacific Coast of the United States.

The extent of the Columbia River Estuary

During spring heavy flow, at its outermost edge the plume may extend miles offshore to as far south as Newport, Oregon. In fall, more a localized feature around the mouth of the river may spread like a narrow jet along the Washington coast, less than offshore.
Winds, and the tidal Coriolis effect also affect its position.
If the Columbia River Estuary is defined by the region that experiences ocean tides, then the estuary extends up the Columbia River to Bonneville Dam and up the Willamette River to Willamette Falls. If the estuary is defined by the geographic land form or by the inland extent of salinity, then the estuary extends only as far as Welch Island.
Settlements on the estuary include Astoria and Warrenton in Oregon, and Ilwaco in Washington. The gathering and retail/wholesale distribution of seafood is a prominent local industry and producer of jobs in the estuary.