Chalk Hill AVA
| Wine region | |
| Type | American Viticultural Area |
|---|---|
| Year established | 1983 1988 Amend |
| Country | United States |
| Part of | California, North Coast AVA, , Sonoma County , Sonoma Coast AVA, Northern Sonoma AVA, Russian River Valley AVA |
| Growing season | 242 days |
| Climate region | Region I-II |
| Heat units | 2,010-2,548 GDD units |
| Precipitation (annual average) | 36 inches (910 mm) |
| Soil conditions | Sandy to silt loam, clay and quartzite high in volcanic ash |
| Total area | 21,120 acres (33 sq mi) 19,840 acres (31 sq mi) |
| Size of planted vineyards | 1,600 acres (650 ha) |
| No. of vineyards | 6 |
| Grapes produced | Cabernet Sauvignon, Chardonnay, Malbec, Merlot, Petit Verdot, Pinot gris, Sangiovese, Sauvignon Blanc, Sauvignon Gris, Semillon, Syrah, Zinfandel |
| No. of wineries | 8 |
Chalk Hill is an American Viticultural Area (AVA) located in Sonoma County, California about eight miles (13 km) north of Santa Rosa. The wine appellation was established on October 21, 1983, as the nation's 49th, the state's 32nd and the county's fourth AVA by the Bureau of Alcohol, Tobacco and Firearms (ATF), Treasury after reviewing the petition submitted by seven local vintners and growers, Donna Maria Vineyards, Blasi Vineyard, Oak Hill Vineyard, Balverne Winery & Vineyards, Landmark Vineyards, DeLoach Vineyards and F. Korbel Bros, proposing a viticultural area in Sonoma County known as "Sonoma Chalk Hill."
ATF proposed to remove the county name "Sonoma" from the appellation name "Sonoma Chalk Hill." The feedback submitted by six of the seven original petitioners stated that the primary purpose for including the county name was to inform consumers that the Chalk Hill area is in Sonoma County. However, the commenters agreed with ATF that this information can be conveyed by placing "Sonoma County" elsewhere on the wine label.
The appellation boundaries outline approximately 21,120 acres (33 sq mi) of the northeast corner within the Russian River Valley AVA. The area is known locally as "Chalk Hill" deriving its namesake from a prominent hill. Another major area geological distinction is the unique "chalky white" tuff in the soil caused by volcanic ash deposited by centuries of volcanic activity from Mount Saint Helena. This "white" soil contributes to the high quality of the fruit produced in the vineyards.
Most of the region's 1,600 acres (650 ha) of cultivated vineyards are located to the east of U.S. Route 101, near the town of Windsor, along the western slopes of the Mayacamas Mountains that rise to elevations from 200 to 1,600 feet (61–488 m). Since 1978, the name "Chalk Hill" has appeared on wine labels produced by a Windsor area winery. Chalk Hill's unique soils performs well with planting of white wine varietals like Chardonnay and Sauvignon Blanc. Its climate is relatively warm due to the influence of a thermal belt that runs through the area. Harvest time often takes place in September while harvest in the surrounding regions usually takes place in October.
In 1988, ATF established a realignment of the boundary common to the Alexander Valley and Chalk Hill viticultural areas so that vineyards immediately within the north-central leg of Chalk Hill, about 1,076 acres (2 sq mi), were relocated to the southeastern corner of the Alexander Valley.