The Siletz River flows about 67 miles (108 km) to the Pacific Ocean through coastal mountains in the U.S. state of Oregon. Formed by the confluence of its north and south forks near Valsetz in Polk County, it winds through the Central Oregon Coast Range. The river, draining a watershed of 373 square miles (970 km²), empties into Siletz Bay, south of Lincoln City in Lincoln County.