Yamhill-Carlton District is an AVA (American Viticultural Area) in the northern Willamette Valley, 35 miles (55km) south of Portland. Pinot Noir is the area's star grape variety, producing soft red wines that display savory, earthy flavors, dark fruits and hints of dark chocolate. Small quantities of Pinot Gris and Chardonnay are also produced.
The district lies in a horseshoe-shaped bank of hills in the north-western corner of the Willamette Valley, nestled against the eastern slopes of the Oregon Coast Range. The Chehalem Mountains lie directly to the east and the Dundee Hills AVA is in the south-east. The small towns of Yamhill and Carlton can be found on the valley floor, providing a picturesque center for the region's boutique wine industry.
Like many AVAs in the Willamette Valley, Yamhill-Carlton District is defined by its elevation, and only land between 200ft and 1000ft (60-300m) above sea level is included within the boundaries of the AVA. This means that all of its vineyards sit on the south-facing slopes of the hills, with land below this considered too fertile and frost-prone to be useful viticulturally.
Yamhill-Carlton District's other distinctive feature is its soil, which is composed of marine sediments deposited by the uplift of an ancient sea floor. These soils, covered in sandy loam, are among the oldest in the Willamette Valley. The surrounding AVAs are characterized by relatively young volcanic soils and by silt deposition from Ice-Age floods that swept through the valley 15,000 years ago. By contrast, Yamhill-Carlton District's free-draining soils encourage low vigor and early ripening, leading to lower acidity in the finished wines.
The cool-climate district lies in the rain shadow of the Coast Range and is also protected by the Chehalem Mountains from the seasonal extremes of the weather systems from the Columbia Valley in the north-west. It is warmer and drier than the McMinnville AVA and the Eola-Amity Hills AVA in the south, and a large fluctuation in temperatures between day and night contribute complexity and structure to the wines produced here.
The first vineyards were planted in the Yamhill-Carlton District AVA in the 1970s, as pioneering growers began to look beyond California for suitable environments in which to grow Pinot Noir. Despite the region's long history, it was not recognized as an AVA until 2004, a full 20 years after the Willamette Valley was delimited as such.
