Willapa Bay is fairly shallow and is an estuary of the Willapa River. The bay itself is bordered only by several smaller towns and unincorporated communities such as Raymond, South Bend, and Tokeland. The bay is entirely located within Pacific County, Washington and is home to a local oyster and seafood processing industry.
Willapa Bay is known for its amazing biodiversity and much of it has been set aside as part of the Willapa National Wildlife Refuge. The bay's ecology is threatened by the rapid spreading of atlantic cordgrass (Spartina Alterniflora), a non-native species of grass introduced to help preserve wetlands and marsh areas.