Grays River (Washington)

Grays River
Name origin: Robert Gray
Country	United States
State	Washington
County	Wahkiakum, Pacific
Source	Willapa Hills
- coordinates	46°28′57″N 123°23′46″W / 46.48250°N 123.39611°W / 46.48250; -123.39611
Mouth	Grays Bay
- location	Columbia River
- elevation	0 ft (0 m)
- coordinates	46°18′10″N 123°41′18″W / 46.30278°N 123.68833°W / 46.30278; -123.68833Coordinates: 46°18′10″N 123°41′18″W / 46.30278°N 123.68833°W / 46.30278; -123.68833
Length	30 mi (48 km)
Basin	124 sq mi (321 km2)
Location of the mouth of Grays River in Washington

Grays River is a tributary of the Columbia River, approximately 30 miles (48 km) long, in southwestern Washington in the United States. One of the last tributaries of the Columbia on the Washington side, it drains an area of low hills north of the mouth of the river.

Grays River rises in the eastern Willapa Hills in southwestern Pacific County. It flows generally southwesterly across western Wahkiakum County. The river has three fork tributaries, the East Fork, South Fork, and West Fork Grays River. Below the West Fork confluence the main river valley broadens. Washington State Route 4 passes through the valley and the communities of Grays River and Rosburg. Fossil Creek joins Grays River above the highway and villages. Hull Creek joins from the north after passing through the village of Grays River. Roughly 5 miles (8.0 km) southwest of the village of Grays River, the river enters the broad portion of the Columbia River's tidal estuary from the north, at Grays Bay, about 15 miles (24 km) upstream from the Columbia's mouth. Grays River becomes tidal at the village of Grays River. In its lower course, especially below Rosburg, the river broadens due to the influence of tides.

The hills and ridges that separate Grays River's watershed from other watersheds is called the Grays River Divide. Rivers whose watersheds lie across the Grays River Divide include the Elochoman River, Chehalis River, Willapa River, and Naselle River. The short Deep River lies just west of Grays River and, like Grays River, empties into Grays Bay.

In 1841 Charles Wilkes of the United States Exploring Expedition charted the river, calling it "Ebokwol". In 1853 it was given another Indian name, "Moolhool", the name used by the Chinookan-speaking natives of the area.