The McMinnville 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 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...

, roughly running from McMinnville

McMinnville, Oregon

McMinnville is the county seat and largest city of Yamhill County, Oregon, United States. According to Oregon Geographic Names, it was named by its founder, William T. Newby , an early immigrant on the Oregon Trail, for his hometown of McMinnville, Tennessee...

 to Sheridan

Sheridan, Oregon

Sheridan is a city in Yamhill County, Oregon, United States. Platted in the 1860s when it received a post office, the city was incorporated in 1880. A major fire burned much of the city in 1913, and a flood covered much of the city in 1964...

. The AVA was created as a result of a successful petition from Kevin Byrd of Youngberg Hill Vineyards. McMinnville is one of few AVAs that is designated in part based on elevation

Elevation

The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

, with vineyards required to be between 200 feet (61 m) and 1000 feet (305 m) above sea level, where the soil and rock formations differ from surrounding areas. Primarily uplifted marine sedimentary loam

Loam

Loam is soil composed of sand, silt, and clay in relatively even concentration . Loam soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils...

s and silt

Silt

Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...

, the top soil is shallow and relatively infertile.