Lewis and Clark River Bridge, Bascule bridge in Clatsop County, Oregon, United States.

The Lewis and Clark River Bridge is a bascule bridge that spans the river with a movable section designed to lift and allow water traffic to pass underneath. The structure is carried by timber piles and supports U.S. Route 101 Business traffic.

The Lewis and Clark River Bridge opened in 1925, replacing a swing-span bridge built at the same spot around 1910. It was designed by Conde McCullough and carried the original U.S. Route 101, now signed as U.S. Route 101 Business.

The bridge carries the name of Meriwether Lewis and William Clark, whose 1804–1806 expedition crossed the American West and reached the Pacific at the mouth of the Columbia, just north of here. The river below and the bridge above both bear their names, so the crossing repeats the explorers' route in local geography.

Visitors can cross the bridge on foot or by car and watch the opening mechanism in action when boats pass through. It is easily accessible from the highway and offers good views of the river and surrounding area.

The bridge's bascule main span measures 112 feet (34 m), while its approaches are made up of 48 timber pile and stringer spans. The total structure runs 828 feet (252 m) across the Lewis and Clark River.