The Cucamonga Valley 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....

 in San Bernardino County

San Bernardino County, California

San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...

, 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...

, about 15 miles (24 km) west of San Bernardino

San Bernardino, California

San Bernardino is a city located in the Riverside-San Bernardino metropolitan area , and serves as the county seat of San Bernardino County, California, United States...

. Grape

Grape

A grape is a non-climacteric fruit, specifically a berry, that grows on the perennial and deciduous woody vines of the genus Vitis. Grapes can be eaten raw or they can be used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, molasses and grape seed oil. Grapes are also...

 cultivation began in the Cucamonga Valley

Cucamonga Valley

The Cucamonga Valley is a region between the Los Angeles and San Bernardino areas, in San Bernardino County and Riverside County, of California, United States. It is located east of the Pomona Valley and it is a major site of wine production and is the location of the Cucamonga Valley AVA, a...

 in 1838, and quickly became a major agricultural crop for the area. When Prohibition

Prohibition in the United States

Prohibition in the United States was a national ban on the sale, manufacture, and transportation of alcohol, in place from 1920 to 1933. The ban was mandated by the Eighteenth Amendment to the Constitution, and the Volstead Act set down the rules for enforcing the ban, as well as defining which...

 began in 1920, the Cucamonga Valley produced more wine grapes than Napa County

Napa County wine

Napa County wine is wine made in Napa County, California, USA. County names in the United States automatically qualify as legal appellations of origin for wine produced from grapes grown in that county and do not require registration with the United States Department of the Treasury Alcohol and...

 and Sonoma County

Sonoma County wine

Sonoma County wine is wine made in Sonoma County, California, USA. County names in the United States automatically qualify as legal appellations of origin for wine produced from grapes grown in that county and do not require registration with the United States Department of the Treasury, Alcohol...

 combined. Following Prohibition, the wine industry and other agricultural endeavors in the Cucamonga Valley faced increasing pressure from the urban expansion of Los Angeles and Orange County

Orange County, California

Orange County is a county in the U.S. state of California. Its county seat is Santa Ana. As of the 2010 census, its population was 3,010,232, up from 2,846,293 at the 2000 census, making it the third most populous county in California, behind Los Angeles County and San Diego County...

. Cucamonga Valley is a hot climate for viniculture, with summer temperatures often exceeding 100 °F (38 °C). The valley floor is sandy, alluvial soils. Pierce’s disease

Xylella fastidiosa

Xylella fastidiosa, a bacterium in the class Gammaproteobacteria, is an important plant pathogen that causes phoney peach disease in the southern United States, oleander leaf scorch, and Pierce's disease, and citrus variegated chlorosis disease in Brazil.-Pierce's disease:Pierce's disease was...

has affected vines in the valley.