Willamette River
Source Confluence of middle and coast forks
Mouth Columbia River
Length 300 km
Basin Area 29,730 km²

The Willamette River is the largest river, by volume, completely in Oregonian Cascadia. It flows south to north through the fertile Willamette Valley, home to Oregon's largest cities, including Portland, Eugene, Corvallis, and Salem. The Willamette valley is known for its agricultural output, including grass seed, hazelnuts, Christmas trees, hops, and vinfera (wine grapes).