About Willamette Valley
The Willamette Valley is a 150-mile (240 km) long valley in the Pacific Northwest region of the United States. The Willamette River flows the entire length of the valley, and it is surrounded by mountains on three sides – the Cascade Range to the east, the Oregon Coast Range to the west, and the Calapooya Mountains to the south. It forms the cultural and political heart of Oregon, and is home to approximately 70 percent of its population including its three largest cities: Portland, Eugene and Salem, the state capital.
The valley may be loosely defined as the broad plain of the Willamette, bounded on the west by the Oregon Coast Range and on the east by the Cascade Range. It is bounded on the south by the Calapooya Mountains, which separate the headwaters of the Willamette from the Umpqua River valley about 25 miles (40 km) south of Hidden Valley. Interstate 5 runs the length of the valley, linking its major communities.
Cities in the valley include, from south to north, Cottage Grove, Eugene, Corvallis, Albany, Dallas, Salem, McMinnville, Oregon City, Hillsboro, Portland, and St. Helens. Parts of the following counties, from south to north, lie within the valley: Douglas, Lane, Linn, Benton, Polk, Marion, Clackamas, Yamhill, Washington, Multnomah, and Columbia.