The Cosumnes River 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 Sacramento County

Sacramento County, California

Sacramento County is a county in the U.S. state of California. Its county seat is Sacramento, which is also the state capital. As of 2010 the county had a population of 1,418,788....

 and San Joaquin County

San Joaquin County, California

San Joaquin County is a county located in Central Valley of the U.S. state of California, just east of the San Francisco Bay Area. As of the 2010 census, the population was 685,306. The county seat is Stockton.-History:...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. Located mostly in Sacramento County, the region is part of the larger Lodi AVA

Lodi AVA

Lodi AVA is an American Viticultural Area located in the Central Valley of California, at the northern edge of the San Joaquin Valley east of San Francisco Bay. The AVA gained approval as a designated wine growing area in 1986 and includes of which are currently planted with wine grapes...

 and includes a portion of the lower Cosumnes River

Cosumnes River

The Cosumnes River is a river in northern California in the United States. It rises on the western slope of the Sierra Nevada and flows approximately into the Central Valley, emptying into the Mokelumne River in the Sacramento-San Joaquin Delta.-Name:...

. Elevations in the AVA range from about 5 feet (2 m) to 48 feet (15 m) above sea level. At these low elevations, frequent fog

Fog

Fog is a collection of water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated...

keeps the Cosumnes River AVA cooler than other regions of Lodi.