Diamond Mountain District AVA
| Wine region | |
| Type | American Viticultural Area |
|---|---|
| Year established | 2001 |
| Years of wine industry | 158 |
| Country | United States |
| Part of | California, North Coast AVA, Napa County, Napa Valley AVA |
| Other regions in California, North Coast AVA, Napa County, Napa Valley AVA | Los Carneros AVA, Howell Mountain AVA, Wild Horse Valley AVA, Stags Leap District AVA, Mt. Veeder AVA, Coombsville AVA Atlas Peak AVA, Spring Mountain District AVA, Oakville AVA, Rutherford AVA, St. Helena AVA, Chiles Valley AVA, Yountville AVA, Oak Knoll District of Napa Valley AVA, Calistoga AVA |
| Growing season | 232 days |
| Climate region | Region I-II |
| Heat units | 2,018-2,894 GDD units |
| Precipitation (annual average) | 55 inches (1,397 mm) |
| Soil conditions | Residual upland soils derived from volcanic parent material |
| Total area | 5,000 acres (8 sq mi) |
| Size of planted vineyards | 500 acres (202 ha) |
| No. of vineyards | 41 |
| Grapes produced | Cabernet Franc, Cabernet Sauvignon, Malbec, Merlot, Petit Verdot, Sauvignon Blanc |
| No. of wineries | 47 |
Diamond Mountain District is an American Viticultural Area (AVA) located in Napa County California in the northwest portion of the Napa Valley landform and appellation. It was established as the nation's 145th, the state's 87th and the county's twelfth AVA on June 1, 2001 by the Bureau of Alcohol, Tobacco and Firearms (ATF), Treasury after reviewing the petition submitted by Rudy von Strasser of Von Strasser Winery, on behalf of the Diamond Mountain Appellation Committee, representing 15 growers and vintners proposing a viticultural area in Napa Valley named "Diamond Mountain."
The AVA boundaries are defined by the Napa-Sonoma county line to the west, Petrified Forest to the north, the 400-foot (122 m) line of altitude running parallel to Route 29 on the east, and the Spring Mountain District to the south. This places the southern part of the city of Calistoga in the appellation, with the northern part located in the Calistoga AVA since 2010. The appellation sits at a higher elevation than most of Napa Valley's wine region, resulting in less cool fog coming in from San Pablo Bay, and more direct exposure to sunlight. The soil is also very porous which allows it to cool down quickly despite the increased sunlight.