Big Valley District-Lake County AVA

Big Valley has a long history of agriculture stretching back to the mid-19th century. Early settlers named it the 'garden spot of Lake County,' recognizing its fertile soils. In the 1960s, Big Valley growers rediscovered the region's winegrape potential, planting the first new vineyards in Lake County since Prohibition. Once part of the ancient lakebed of Clear Lake, the area was the first settlement in Lake County and has a continuous record of agricultural activity. The TTB formally established the Big Valley District-Lake County AVA on October 2, 2013, with the rule taking effect November 1, 2013.

• Written references to 'Big Valley' date to at least 1881, with the name carrying local and historical significance throughout Lake County
• At official designation the region contained 6 bonded wineries, 43 vineyards, and roughly 1,800 acres of cultivated grapes
• Established concurrently with the adjacent Kelsey Bench-Lake County AVA; both nest within the larger Clear Lake AVA and North Coast AVA
• The 1960s viticultural revival was driven by growers such as the Holdenried family, fifth-generation Lake County farmers who planted Zinfandel in 1966 and later founded Wildhurst Winery in 1991

Big Valley District occupies a wide, predominantly flat valley on the western shore of Clear Lake, just northwest of Mount Konocti. Its boundaries run from Clear Lake to the north, Mount Konocti and the Red Hills-Lake County AVA to the east, Merritt Road and Bell Hill Road to the south, and Highland Springs Road to the west. The AVA's flat topography means cold air does not drain naturally off the vineyards in early spring and late fall, resulting in less diurnal temperature variation than mountainous Lake County AVAs and favoring varieties with shorter growing seasons. Clear Lake moderates summer temperatures: afternoon breezes cool the canopy, slow ripening, and help stave off mildew and fungal disease.

• Vineyard elevations of 1,330 to 1,440 feet are among the lowest in Lake County; the county overall sits well above sea level, buffering vineyards from extreme heat
• Growing degree day averages of 2,878 to 3,124 (2005–2010) place Big Valley significantly cooler than the neighboring Red Hills AVA (3,544–3,620 GDD)
• Lake breezes are strong enough to dry the vine canopy, reducing fungal disease pressure during the growing season
• The evolving watershed has cut gravel deposits and swaths of well-drained soils through the otherwise clay-dominant valley floor, creating variation across vineyard sites

Big Valley's soils set it apart from every other Lake County AVA. While volcanic soils dominate the Red Hills, High Valley, and Kelsey Bench AVAs, Big Valley is defined by deep alluvial clay and loam derived from lacustrine and alluvial materials. The three dominant soil series, Cole clay loam, Clear Lake clay, and Still loam, together account for approximately 74 percent of the AVA. These soils are very deep, nearly level, and brown to dark brown, with a pH ranging from slightly acidic to mildly alkaline. Their heavy clay content naturally curbs vine vigor and limits yields, concentrating flavors, but drainage management is critical since the soils are not naturally well-drained and vines risk waterlogging.

• Cole clay loam formed on alluvial floodplain materials; Clear Lake clay formed in lacustrine deposits; Still loam is a deep, well-drained alluvial plain soil with gravelly layers
• Approximately 65 percent of Big Valley soils fall within the optimal pH range of 6.0 to 7.5 for nutrient uptake
• Hard clay subsoil beneath the rooting zone can limit root depth, making vines more vulnerable during drought years
• Volcanic material eroded from nearby Mount Konocti contributes minor volcanic influences to an otherwise sedimentary soil profile

Sauvignon Blanc is the most widely planted variety in Big Valley District and the wine for which the region is best known, recognized for producing light, dry, and flinty expressions. The heavy clay soils and lake-moderated climate suit its earlier-ripening character well. The region also grows Chardonnay, Viognier, Riesling, Cabernet Franc, Zinfandel, and Merlot. Gravel seams running through the valley floor are particularly valued for producing intense and balanced Zinfandel and Cabernet Franc. The contrast between Big Valley's sedimentary low-elevation soils and the volcanic mountainous soils of Red Hills and High Valley allows for distinctly different expressions of shared varieties across the county.

• Sauvignon Blanc from Big Valley expresses light, dry, and flinty character, driven by cool lake breezes, clay soils, and moderate growing degree days
• Kelsey Bench and Big Valley gravel seams produce intense, balanced Zinfandel and Cabernet Franc alongside the dominant white varieties
• Deep clay soils naturally limit vigor and yields, concentrating berry flavors, though waterlogging risk requires attentive canopy and irrigation management
• Lake County Sauvignon Blanc, with Big Valley as a key source, is increasingly recognized as one of California's premier expressions of the variety

At the time of designation, six bonded wineries operated within Big Valley District. The region's producer base includes some of Lake County's most established names. Wildhurst Vineyards, founded by the fifth-generation Holdenried farming family in Kelseyville, is best known for its Sauvignon Blanc and produces a wide range of Lake County varieties across 400 acres of estate vineyards. Steele Wines, founded by former Kendall-Jackson head winemaker Jed Steele in 1991 and based in Lakeport, sources Lake County fruit and is a longstanding champion of the region. Vigilance Winery, part of the Shannon Family of Wines, produces affordable, critically praised Sauvignon Blanc and Cabernet Sauvignon from Lake County fruit.

• Wildhurst Vineyards, Kelseyville: 400 acres of estate vineyards; best known for Sauvignon Blanc, Petite Sirah, and Cabernet Sauvignon
• Steele Wines, Lakeport: founded 1991 by Jed Steele, former head winemaker at Kendall-Jackson; produces Lake County Sauvignon Blanc and Cabernet Sauvignon under both Steele and Shooting Star labels
• Approximately 80 percent of Lake County grapes are sold to wineries in neighboring Napa, Sonoma, and Mendocino counties for blending or appellation use under the North Coast designation
• A slow industry resurgence from the late 1990s and 2000s brought new producers including Brassfield Estate, Shannon Ridge, Gregory Graham Wines, and Chacewater Winery to Lake County

The TTB established the approximately 11,000-acre Big Valley District-Lake County AVA on October 2, 2013, with an effective date of November 1, 2013 (T.D. TTB-118). The AVA was established because its geographical features, particularly its alluvial clay soils and flat topography near Clear Lake, are distinctly different from the surrounding Clear Lake and North Coast viticultural areas. Big Valley District is fully nested within both the Clear Lake AVA and the multicounty North Coast AVA. Under standard California labeling rules, a wine may carry the Big Valley District appellation if 85 percent or more of its grapes originate from within the AVA boundaries.

• TTB docket TTB-2013-0003, T.D. TTB-118: final rule published October 2, 2013; effective November 1, 2013
• Nested AVA hierarchy: Big Valley District is within Clear Lake AVA, which is within North Coast AVA; wines may be labeled at any of these appellation levels
• Major soil series Cole clay loam, Clear Lake clay, and Still loam account for approximately 74 percent of the AVA and were central to the petition's evidence of distinctiveness
• The Red Hills Lake County AVA boundary was also modified at the same time to align with the newly created Kelsey Bench AVA border

Big Valley District maintains a quietly agricultural wine country atmosphere centered around the town of Kelseyville, which serves as the hub for several tasting rooms. The Lake County Winegrape Commission, headquartered at 3865 Main Street in Kelseyville, is a useful resource for visitors planning tastings across the county's AVAs. The drive from San Francisco takes approximately two hours north via Highway 29 over Mount St. Helena, making the region accessible for day trips or weekend visits. Clear Lake, California's largest natural freshwater lake, anchors the region and offers abundant outdoor recreation including fishing, kayaking, and hiking.

• Kelseyville serves as the main hub for Big Valley District tasting rooms, including Wildhurst Vineyards on Benson Lane and Steele Wines on Thomas Drive in Lakeport
• Lake County is located approximately 60 miles north of San Francisco; Highway 29 north from Calistoga over Mount St. Helena reaches Middletown and the lake basin
• Clear Lake, the largest natural freshwater lake in California, provides the backdrop for the region and moderates the local climate year-round
• Best visited during the harvest season (September to October) or spring (April to May) when temperatures are moderate and tasting rooms are most active