The Smith River is a 40 km long river in Del Norte County in the far northwest of the US state of California. The Smith River was named after the adventurer and trapper Jedidiah Smith, who explored the region in 1828.
The Smith River originates near Gasquet at the confluence of the North Fork and Middle Fork Smith Rivers. It initially flows 5 kilometers to the west, then 7 kilometers to the south-southwest. The South Fork Smith River enters the river from the left. The Smith River flows west past Hiouchi and then turns north-northwest. The Jederdiah Smith Redwoods State Park is located on the left bank of the river. The Smith River leaves the mountainous region and flows into the Pacific Ocean 20 km north of Crescent City. At its mouth, the river forms a long estuary that runs parallel to the coast. The town of Smith River is located 2 km east of the river mouth on the U.S. Highway 101. The U.S. Highway runs between Gasquet and Hiouchi. Highway 199 along the river. The approximately 1,877 km² basin (including approximately 1,579 km² in California and 298 km² in Oregon) extends across the Klamath Mountains and includes parts of the Rogue River-Siskiyou National Forest and Six Rivers National Forest as well as the Smith River National Recreation Area. To the south it is bordered by the Klamath River basin and to the north by the Chetco River and Rogue River.