Most of Oregon's best wines come from a group of small appellations that make up the Willamette Valley, in the northwest corner of the state.
It is here that Oregon's specialty — pinot noir, a delicate and temperamental grape considered by many to make the most sensual red wines in the world — reaches its fullest expression.
The valley's relatively cool, marginal climate, with about 40 inches (102 centimetres) of rain a year and the risk of frost in spring and fall, is the major factor in the elegance that characterises Oregon's top wines: grapes cannot burst into ripeness but must make their way slowly and methodically toward maturity and complexity.
Willamette Valley is one of the American Viticultural Areas named on US labels alongside Napa Valley, the Finger Lakes and Columbia Valley.