The Smith River (Tolowa: ) flows from the Klamath Mountains to the Pacific Ocean in Del Norte County in extreme northwestern California, on the West Coast of the United States. The river, about 25.1 miles (40.4 km) long, all within Del Norte County, flows through the Rogue River – Siskiyou National Forest, Six Rivers National Forest, and Jedediah Smith Redwoods State Park.
Course
right|thumb|300px|The [[confluence of the South Fork with the main Smith River near Crescent City, California]]
The Smith River is formed by the confluence of its Middle Fork and North Fork, near the community of Gasquet. The Middle Fork, long, The South Fork Smith River enters the Smith River near the community of Hiouchi. The
Watershed
The river's watershed catchment area is . It drains a rugged area of the western Klamath Mountains and Northern Outer California Coast Ranges, west of the Siskiyou Mountains, barely across the Oregon border, and north of the watershed of the Klamath River.
By average discharge, the Smith is the largest river system in California that flows freely along its entire course. The highly variable annual flow is approximately , with an average monthly high of in January, and an average low of in September. The all-time highest flow was on December 22, 1964, during the Christmas flood of 1964.
Conservation
The free-flowing nature of the river—without a single dam along its entire length—makes it especially prized among conservationists and is considered one of the crown jewels of the National Wild and Scenic River program. It is the only major California river never to have been dammed.
thumb|320px|Former Smith River Bridge crossing the Lower Smith River.
thumb|Former [[cantilever bridge|cantilever highway truss of Smith River Bridge.]]
Crossings
The 1929 Smith River Bridge, also known as the Hiouchi Bridge or Bridge Wo. 1-06, was a rare example of a cantilever highway truss bridge within California, until it was demolished in 1989. The two-lane road bridge carried U.S. Highway 199 across the Smith River. The structural steel components were fabricated by Virginia Bridge & Iron Co. in Roanoke, shipped via the Panama Canal to San Francisco, then reloaded to a smaller coastal vessel and shipped to Crescent City. The suspended center span was a Parker truss.