The Willamette Valley is the watershed of the Willamette River in the state of Oregon. The Willamette River drains both the Cascade Mountains and the Coast Range, and its many tributaries reach far into both mountain ranges. But apart from it being a physical feature, the Willamette Valley also denotes the economic and social center of Oregon. Although the Willamette Valley contains around 10% of Oregon's area, it contains around three-quarters of its population. Of Oregon's ten largest cities, eight are in the Willamette Valley, and of its twenty largest, sixteen are. The corridor of the Willamette Valley, running from Eugene, Oregon, through Corvallis and Albany, the state capital of Salem, Oregon and finally up to the Portland area, with its attendant suburbs, is where most of Oregon's business goes on, and which probably fits people's stereotypical version of Oregon. Along this route, the river more or less parallels the I-5 Freeway.
The Willamette Valley was settled by Europeans because it has very fertile soil and the rain and mild weather make it a prime growing region. The Willamette River also made transportation easy, especially for the early logging industry. Despite this start, it is probably only in Albany and Linn County that timber and farming play a primary role in the economy. Portland has a diversified economy, while Salem is based on the governmental sector, and Eugene and Corvallis are homes of two of Oregon's state schools. Although the Willamette Valley is about 100 miles from Eugene to Portland, it can sometimes be looked at as a single urbanization area, with a high degree of mobility and interchange between the cities on its length.