Located at the southwestern edge of Washington, Willapa Bay would be part of the Pacific Ocean, were it not for the 25-mile strip of sand known as the Long Beach Peninsula. The shallow bay is the estuary of the Willapa River, which passes through Raymond and South Bend before reaching the bay.
There are no major communities on the mainland side of the bay itself. Tokeland is a small community on the north shore and Oysterville and Nahcotta are on the inland side of the Long Beach Peninsula.
The bay is a major wildlife resource and significant parts have been set aside in the Willapa National Wildlife Refuge.