|Source||Confluence of middle and coast forks|
|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).