The Sonoita 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 southeast Arizona

Arizona

Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

, south of the city of Tucson

Tucson, Arizona

Tucson is a city in and the county seat of Pima County, Arizona, United States. The city is located 118 miles southeast of Phoenix and 60 miles north of the U.S.-Mexico border. The 2010 United States Census puts the city's population at 520,116 with a metropolitan area population at 1,020,200...

. The Sonoita area is a basin surrounded by three mountain ranges, the Huachuca Mountains

Huachuca Mountains

The Huachuca Mountain range is part of the Sierra Vista Ranger District of the Coronado National Forest. The Huachuca Mountains are located in Cochise County, Arizona approximately south-southeast of Tucson and southwest of the city of Sierra Vista, Arizona...

, the Santa Rita Mountains

Santa Rita Mountains

The Santa Rita Mountains, located about 65 km southeast of Tucson, Arizona, extend 42 km from north to south, then trending southeast. They merge again southeastwards into the Patagonia Mountains, trending northwest by southeast...

, and the Whetstone Mountains

Whetstone Mountains

The Whetstone Mountains are a mountain range in southeastern Arizona. Major ranges in the region are part of sky island ranges called the Madrean Sky Islands. Part of the Coronado National Forest, the range is one of the least accessible areas...

. The vineyard plantings are 4500 to 5000 ft (1,371.6 to 1,524 m) above sea level, some of the highest in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. The soil is alluvial fan

Alluvial fan

An alluvial fan is a fan-shaped deposit formed where a fast flowing stream flattens, slows, and spreads typically at the exit of a canyon onto a flatter plain. A convergence of neighboring alluvial fans into a single apron of deposits against a slope is called a bajada, or compound alluvial...

s of gravel

Gravel

Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

ly 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...

that retains scarce water well.