Willamette River

The Willamette River is a tributary of the Columbia River, about 240 mi (386 km) long, in northwestern Oregon in the United States. Flowing northward between the Coastal Range and Cascade Range, the river and its tributaries form a basin called the Willamette Valley containing the largest population centers of Oregon, with Portland, which sits along both sides of the river near its mouth on the Columbia. Its lush valley is fed by prolific rainfall on the western side of the Cascades, forming one of the most fertile agricultural regions of North America that was the destination for many if not most of the emigrants along the Oregon Trail. The river was an important transportation route all over much of the early history of the state, furnishing a means of conveying the vast timber and agricultural resources of the state to the outside world.