Skamokawa Valley is a census-designated place (CDP) in Wahkiakum County, Washington, north of the town of Cathlamet. The population was 401 as of the 2010 census. The CDP includes the Sleepy Hollow community. The Skamokawa Valley community is part of the Wahkiakum School District, a K-12 school district of about 430 students. The name of the CDP comes from that of the Wahkiakum Chief Skamokawa who met with Meriwether Lewis and William Clark while their expedition spent the winter of 1805-06 at Fort Clatsop. His name, Skamokawa, is a Chinook word meaning “smoke over the water,” a reference to the area's foggy climate.