Grays Harbor is an
estuarine bay located north of the mouth of the
Columbia River, on the southwest
Pacific coast of
Washington state, in the
United States of America. It is a
ria, which formed at the end of the last ice age, when sea levels flooded the
Chehalis River. The bay is long and wide. The
Chehalis River flows into its eastern end, where the city of
Aberdeen stands at that river's mouth, on its north bank, with the somewhat smaller city of
Hoquiam immediately to its northwest, along the bayshore. Besides the Chehalis, many lesser rivers and streams flow into Grays Harbor, such as
Hoquiam River and
Humptulips River. A pair of low peninsulas separate it from the Pacific Ocean, except for an opening about two miles (3 km) in width. The northern peninsula, which is largely covered by the community of
Ocean Shores, ends in Point Brown. Facing that across the bay-mouth is Point Chehalis, at the end of the southern peninsula upon which stands the town of
Westport.