| Cedar River | |
| Map Size: | 300 |
| Pushpin Map: | USA Washington |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the Cedar River in Washington |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Washington |
| Subdivision Type4: | County |
| Subdivision Name4: | Pacific |
| Length: | 8miles[1] |
| Source1: | Willapa Hills |
| Source1 Coordinates: | 46.7628°N -124.0547°W |
| Source1 Elevation: | 165feet[2] |
| Mouth: | Willapa Bay |
| Mouth Location: | Tokeland, Washington |
| Mouth Coordinates: | 46.7361°N -123.975°W |
| Mouth Elevation: | 0feet |
The Cedar River is a short stream flowing into the north end of Willapa Bay in the U.S. state of Washington.
The Cedar River originates near Seastrand Ridge in the Willapa Hills, about a mile east of the Pacific Ocean near Heather and Grayland Beach State Park, just south of Grayland. It flows east, then south, for about 8miles until emptying into the northern end of Willapa Bay near Tokeland, just east of Dexter by the Sea.[3]
The river's lowermost course runs through part of the North Willapa Bay Wildlife Area Unit,[4] part of the Johns River Wildlife Area.[5]
The mouth of the Cedar River merges with Willapa Bay in a tidally-influenced estuary. There is a 275 acre protected unit called the Cedar River Estuary, managed by Forterra. This area is a tidal ecosystem with salt marshes, tidelands, and coniferous forests. It also includes Oyster Island, Bone Creek, and Norris Slough.[6]