The Lewis and Clark River is a tributary of Youngs River, approximately 20 miles (32 km) long, in northwest Oregon in the United States. It drains 62 square miles (160 km2) of the Northern Oregon Coast Range in the extreme northwest corner of the state, entering Youngs River just above its mouth on the Columbia River at Youngs Bay. Near the river's mouth is the site of former Fort Clatsop of the Lewis and Clark Expedition. The river is named for Meriwether Lewis and William Clark.