The Yamhill-Carlton District AVA is an American Viticultural Area

American Viticultural Area

An American Viticultural Area is a designated wine grape-growing region in the United States distinguishable by geographic features, with boundaries defined by the Alcohol and Tobacco Tax and Trade Bureau , United States Department of the Treasury....

 located in both Washington County

Washington County, Oregon

- Major highways :* Interstate 5* Interstate 205* U.S. Route 26* Oregon Route 6* Oregon Route 8* Oregon Route 10* Oregon Route 47* Oregon Route 99W* Oregon Route 210* Oregon Route 217* Oregon Route 219-Demographics:...

 and Yamhill County

Yamhill County, Oregon

-National protected areas:*Siuslaw National Forest *Tualatin River National Wildlife Refuge -Demographics:As of the census of 2000, there were 84,992 people, 28,732 households, and 21,376 families residing in the county. The population density was 119 people per square mile . There were 30,270...

, Oregon

Oregon

Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

. It is entirely contained within the Willamette Valley AVA

Willamette Valley AVA

The Willamette Valley AVA , is an American Viticultural Area which lies in the Willamette Valley of Oregon. The AVA is the wine growing region which encompasses the drainage basin of the Willamette River...

, and surrounds the towns of Carlton

Carlton, Oregon

Carlton is a city in Yamhill County, Oregon, United States. According to the 2000 United States Census, the municipality population was 1,514. The 2007 estimate is 1,755 residents.-History:...

 and Yamhill

Yamhill, Oregon

Yamhill is a city in Yamhill County, Oregon, United States. Located in the northern part of the county, it is situated at the intersection of Oregon Route 47 and Oregon Route 240. The population was 794 at the 2000 census. The 2008 estimate is 855 residents...

. The mountain ridges surrounding the district form a horseshoe

Horseshoe

A horseshoe, is a fabricated product, normally made of metal, although sometimes made partially or wholly of modern synthetic materials, designed to protect a horse's hoof from wear and tear. Shoes are attached on the palmar surface of the hooves, usually nailed through the insensitive hoof wall...

 shape, and most of the vineyards are located on south-facing slopes. The AVA includes only land between 200 feet (61 m) and 1000 feet (305 m) above sea level where marine sediments are some of the oldest soils in the Willamette Valley and create unique conditions for viticulture

Viticulture

Viticulture is the science, production and study of grapes which deals with the series of events that occur in the vineyard. When the grapes are used for winemaking, it is also known as viniculture...

. The region is in the rain shadow

Rain shadow

A rain shadow is a dry area on the lee side of a mountainous area. The mountains block the passage of rain-producing weather systems, casting a "shadow" of dryness behind them. As shown by the diagram to the right, the warm moist air is "pulled" by the prevailing winds over a mountain...

 of the 3500 feet (1,066.8 m) Oregon Coast Range

Oregon Coast Range

The Oregon Coast Range, often called simply the Coast Range and sometimes the Pacific Coast Range, is a mountain range, in the Pacific Coast Ranges physiographic region, in the U.S. state of Oregon along the Pacific Ocean...

, a short distance to the west.