Rattlesnake Hills AVA: A Comprehensive Guide
Overview & Location
The Rattlesnake Hills American Viticultural Area represents one of Washington State's most distinctive and promising wine regions. Established as an AVA on March 20, 2006, this relatively young appellation has quickly gained recognition for producing exceptional wines that capture the unique characteristics of its dramatic topography and distinctive terroir.
Located within the larger Yakima Valley AVA, itself nested within the expansive Columbia Valley AVA, Rattlesnake Hills occupies approximately 68,500 acres in south-central Washington State. The AVA takes its name from the prominent Rattlesnake Hills ridge, which forms the northern boundary of the Yakima Valley and creates a dramatic backdrop for the region's vineyards.
Geographically, Rattlesnake Hills sits roughly 140 miles southeast of Seattle and approximately 30 miles southwest of Yakima, Washington's agricultural hub. The region extends along the southern slopes of Rattlesnake Ridge, stretching from the Yakima River in the valley floor to the ridgeline above. The towns of Zillah, Granger, and Outlook serve as the primary communities within the AVA, while the Tri-Cities area (Richland, Kennewick, and Pasco) lies about 50 miles to the southeast.
The AVA's boundaries were carefully defined based on distinguishing features including elevation, slope aspect, soil composition, and climatic patterns that set it apart from surrounding areas. The southern-facing slope orientation of the Rattlesnake Hills creates a distinctive mesoclimate that differentiates this region from the valley floor below and other Yakima Valley sub-appellations.
Climate & Geography
Rattlesnake Hills exemplifies the desert continental climate that characterizes much of eastern Washington's wine country, yet with several unique moderating factors. Situated in the rain shadow of the Cascade Mountains to the west, the region receives a mere 6-8 inches of annual precipitation, far below the threshold needed for unirrigated viticulture. This arid environment necessitates irrigation but provides winemakers with precise control over vine water stress and grape development.
The AVA's most significant climatic feature is its pronounced diurnal temperature shift: the difference between daytime and nighttime temperatures. During the growing season, daytime temperatures frequently reach the upper 80s to mid-90s Fahrenheit (30-35°C), while nighttime temperatures regularly drop into the 50s Fahrenheit (10-15°C). This dramatic swing, often exceeding 40-50°F (22-28°C), allows grapes to develop full physiological ripeness and flavor intensity while retaining crucial natural acidity, resulting in wines with exceptional balance and aging potential.
The elevation profile of Rattlesnake Hills vineyards ranges from approximately 750 feet (230 meters) near the valley floor to over 3,000 feet (915 meters) at the highest vineyard sites along the ridge. This 2,000+ foot elevation gradient creates multiple mesoclimates within the AVA, allowing vintners to select optimal sites for different varieties based on heat accumulation needs.
The topography consists primarily of south and southwest-facing slopes, which receive maximum sun exposure throughout the growing season. This aspect is particularly advantageous in a northern latitude (46°N), extending the effective growing season and ensuring adequate heat accumulation even for later-ripening varieties. The slope angles range from gentle undulations to more dramatic inclines, providing natural air drainage that reduces frost risk: a critical advantage during the vulnerable spring budbreak and fall harvest periods.
Wind plays an important role in Rattlesnake Hills viticulture. Prevailing westerly winds and afternoon thermal updrafts moving from the valley floor help moderate extreme temperatures, reduce disease pressure by keeping canopies dry, and contribute to thicker-skinned, more concentrated grapes. However, these same winds can present challenges during bloom and require careful vineyard management.
Terroir & Soils
The geological story of Rattlesnake Hills is one written by both ancient volcanic activity and catastrophic ice age flooding. The foundation of the region consists of Columbia River Basalt, formed 15-17 million years ago during massive volcanic eruptions that covered much of the Pacific Northwest in layers of flood basalt. This dark volcanic rock underlies the entire region and occasionally outcrops at the surface on higher elevation sites.
The most dramatic influence on the region's soil composition came from the Missoula Floods: a series of cataclysmic events occurring between 15,000 and 13,000 years ago. As glacial ice dams repeatedly formed and broke in what is now Montana, massive walls of water surged westward across Washington State with forces that reshaped the landscape. These floods deposited varied sediments throughout the Columbia Basin, including the Yakima Valley.
In Rattlesnake Hills, the primary soil types reflect this complex geological history. The dominant soil structure consists of wind-blown loess (silty sediment) of varying depths overlying gravel beds, cobblestones, and fractured basalt. Loess depths can range from a few inches on exposed upper slopes to several feet in mid-slope positions. These fine-grained, silt-dominated soils offer excellent drainage while maintaining some moisture-holding capacity: a beneficial combination for viticulture.
At higher elevations, particularly above 1,500 feet, soils become increasingly shallow with greater rock content and more direct basalt influence. These well-drained, low-vigor sites produce smaller berries with high skin-to-juice ratios, yielding intensely concentrated wines. The rocky, fractured basalt subsoil also provides natural drainage and forces roots to dive deep in search of water and nutrients, creating physiological stress that enhances wine quality.
Mid-slope positions typically feature the deepest loess deposits, often 3-6 feet or more, before reaching gravel or basalt layers. These sites balance vine vigor with quality potential, making them versatile for various grape varieties. The silty loess has excellent drainage characteristics despite its fine texture, as the porous structure allows water to percolate readily while the soil particles retain enough moisture to support consistent vine growth.
Lower elevation sites approaching the valley floor show increased alluvial influence, with heavier soils and sometimes poorer drainage. While still viable for viticulture with proper management, these sites generally produce higher yields and less concentrated wines than their upslope counterparts.
The soil pH throughout Rattlesnake Hills tends toward alkaline (7.5-8.5), typical of arid climates, and fertility levels are naturally low to moderate. These conditions promote moderate vine vigor and encourage focused fruit production rather than excessive vegetative growth, ideal for premium wine grape cultivation.
Viticulture
Approximately 1,200 acres of wine grapes are currently planted within the Rattlesnake Hills AVA, though the total suitable acreage is significantly larger. This relatively modest footprint compared to the overall AVA size reflects both the selective nature of premium vineyard development and the fact that much of the terrain remains in other agricultural uses or is unsuitable for viticulture due to elevation extremes or exposure.
The region's viticultural calendar follows the general Washington State pattern but with site-specific variations based on elevation and exposure. Budbreak typically occurs in mid-to-late April, with higher elevation sites breaking later. Bloom follows in early-to-mid June, and veraison (the onset of ripening) usually begins in late July or early August. Harvest extends from late August for early-ripening whites through October for later-ripening reds, with higher elevation vineyards generally harvested later.
Rattlesnake Hills has proven remarkably versatile in terms of grape varieties, successfully growing both cool-climate and warm-climate grapes depending on site selection. Riesling claims significant acreage and has emerged as something of a signature variety for the region. The combination of warm days, cool nights, and well-drained soils produces Rieslings with penetrating aromatics, vibrant acidity, and distinct mineral notes that reflect the basalt subsoils.
Chardonnay also performs exceptionally well, particularly at higher elevations where cooler temperatures preserve acidity and allow for extended hang time. These sites produce structured, age-worthy Chardonnays with bright fruit and mineral complexity rather than the flabby, overripe characteristics common in hotter regions.
Red varieties have found considerable success on mid-to-lower elevation sites with greater heat accumulation. Merlot has historically been important in Rattlesnake Hills and produces supple, fruit-forward wines with softer tannins than many Columbia Valley expressions. Cabernet Sauvignon performs well on favored sites with optimal sun exposure and heat accumulation, producing structured wines with classic varietal character.
Syrah has emerged as an exciting variety in recent plantings, with the diurnal temperature swings helping maintain the spice, pepper, and savory elements alongside ripe fruit. Other varieties grown in smaller quantities include Cabernet Franc, Malbec, Petit Verdot, Viognier, and Gewürztraminer.
The growing season in Rattlesnake Hills accumulates approximately 2,500-3,000 growing degree days (GDD, base 50°F), placing it in a similar range to regions like Burgundy, the Northern Rhône, or Oregon's Willamette Valley, though with very different seasonal patterns. The arid desert environment with irrigation differs markedly from these rainfall-dominated regions but achieves comparable heat accumulation.
Irrigation is universally necessary, with most vineyards utilizing drip systems that allow precise water management. Water rights come primarily from the Yakima River system, though availability can vary seasonally and year-to-year. Sustainable water management has become increasingly important as the region develops.
Viticultural challenges include spring frost management (though slope aspect and air drainage help), occasional winter freeze events (temperatures can drop below 0°F/-18°C in severe winters), wind during bloom that can reduce fruit set, and bird pressure during harvest. The arid climate minimizes fungal disease pressure, reducing the need for spraying: a significant advantage for organic and sustainable viticulture.
Wine Styles
Rattlesnake Hills wines have developed a reputation for balance, elegance, and distinctive minerality that sets them apart from other Columbia Valley expressions. The combination of moderate heat accumulation, significant diurnal shifts, and volcanic soil influence creates wines with ripeness and concentration balanced by natural acidity and structural definition.
Riesling from Rattlesnake Hills has emerged as particularly distinctive. These wines typically show intense aromatics of white flowers, citrus (lime, lemon), stone fruit (peach, apricot), and distinctive mineral notes often described as "flint" or "wet stone." The volcanic soil influence seems particularly evident in the wine's mineral backbone. Styles range from bone-dry to off-dry, with the sugar-acid balance allowing even slightly sweeter expressions to maintain vibrancy and food-friendliness. The natural acidity (often 7-9 g/L or higher) provides excellent aging potential, with premium examples developing honey, petrol, and complex tertiary notes over 5-10+ years.
Chardonnay from the region tends toward a leaner, more mineral-driven profile than many California expressions, though with more fruit intensity than classic Chablis. Winemakers have increasingly moved toward restrained oak usage, allowing the vineyard character to shine through. Typical flavor profiles include green apple, pear, citrus, and subtle tropical notes, with underlying minerality and bright acidity. Malolactic fermentation usage varies by producer and vintage, with many opting for partial or no malo to preserve freshness.
Merlot shows perhaps the most distinctive regional character among the reds. Rattlesnake Hills Merlot typically displays red fruit (cherry, raspberry, plum) rather than the jammy, overripe black fruit common in hotter regions. The wines show herbal complexity (sage, thyme, dried herbs), supple tannins, and medium-to-full body with elegance rather than power. These characteristics make them approachable young while still developing complexity with age.
Cabernet Sauvignon from optimal sites produces structured, age-worthy wines with classic varietal character (cassis, black cherry, cedar, tobacco) but with slightly higher-toned fruit and more evident acidity than many Washington expressions. The wines typically show firm but refined tannins and benefit from 3-5 years of bottle age.
Syrah has shown exciting potential, producing wines that bridge Northern Rhône savory character with New World fruit ripeness. Expect black pepper, cured meat, olive, and dark berry flavors with firm structure and distinctive minerality.
Compared to other Columbia Valley sub-AVAs, Rattlesnake Hills wines generally show more pronounced acidity and mineral character than the warmer Horse Heaven Hills or Red Mountain, more elegance and restraint than the powerful Wahluke Slope, and more consistent ripeness than the cooler Snipes Mountain. Within Yakima Valley, Rattlesnake Hills offers warmer sites than Red Mountain's highest elevations but maintains better acidity than the valley floor.
Price points vary widely based on producer and wine tier. Entry-level wines from large producers might retail for $12-18, while mid-tier estate wines typically range from $20-40. Premium single-vineyard and reserve wines can reach $50-100 or more, particularly for aged Rieslings and Cabernet-based blends.
Notable Producers & Vineyards
Several pioneering producers established Rattlesnake Hills' viticultural reputation and continue to create benchmark wines from the region.
Bonair Winery, established in 1985, stands as one of the AVA's founding estates. The Puryear family planted their estate vineyard and winery on the lower slopes near Zillah, focusing on producing small-lot wines that express specific site characteristics. Their Chardonnays and red blends have consistently demonstrated the region's potential.
Portteus Vineyards & Winery, located on the eastern end of the AVA, has been farming the same site since 1981, making it one of the longest-continuously-farmed vineyards in the region. Their estate wines showcase mature vine character and the distinctiveness of their specific terroir.
Two Mountain Winery has gained recognition for exceptional Riesling and aromatic white wines that highlight the region's mineral character. Their Hidden Horse Vineyard has become a benchmark site for aromatic varieties.
Treveri Cellars focuses on traditional-method sparkling wines, utilizing the region's high-acid base wines to create elegant Washington bubbles. Their success demonstrates the versatility of Rattlesnake Hills fruit.
Wilridge Winery produces small-production wines emphasizing vineyard character and minimal intervention winemaking, showcasing what the terroir can achieve with thoughtful viticulture.
Many prominent Washington wineries source fruit from Rattlesnake Hills even if they're not physically located within the AVA. Harrison Hill Vineyard, planted in 1962, is among Washington's oldest continuously producing vineyards and has supplied fruit for numerous award-winning wines, though it predates the AVA designation.
Dineen Vineyards, Roza Hills Vineyard, Upland Vineyard, and Sheridan Vineyard have emerged as quality sources for numerous producers, with several offering vineyard-designate programs to multiple wineries.
Wine Tourism & Future
Wine tourism in Rattlesnake Hills has grown steadily since the AVA designation, though it remains less developed than some other Washington wine regions. The Yakima Valley Wine Country, of which Rattlesnake Hills is a part, offers a more intimate, agricultural tourism experience compared to the busier Woodinville tasting room corridor near Seattle.
Most wineries are concentrated along or near Highway 82 between Prosser and Yakima, with the Zillah area serving as an informal hub. The region offers a mix of working farm wineries, estate tasting rooms, and agricultural landscapes that provide authentic wine country atmosphere without pretension. Many wineries maintain family-run operations with owners personally hosting visitors, offering insights into both winemaking and the broader agricultural heritage of the Yakima Valley.
The best visiting season runs from April through October, with spring (April-May) offering wildflowers and budbreak, summer providing warm weather and lush vineyards, and fall (September-October) delivering harvest excitement and autumn colors. Winter visits are possible but some smaller wineries operate by appointment only during colder months.
Several annual events draw visitors, including the Spring Barrel Tasting in late April, Catch the Crush harvest events in September and October, and holiday open houses in November and December. These events provide opportunities to taste library wines, barrel samples, and limited releases while meeting winemakers.
The future outlook for Rattlesnake Hills appears promising. Climate change projections suggest the region may see gradual warming and potentially more consistent vintages with reduced frost risk, though water availability remains a long-term concern. The growing recognition of Washington State wines globally positions Rattlesnake Hills to gain increased attention as consumers explore beyond the state's better-known appellations.
Recent years have seen renewed vineyard development, with several new plantings targeting premium sites at higher elevations. There's increasing focus on sustainable and organic viticulture, with some producers pursuing formal certifications. The diversity of successful grape varieties positions the region well to adapt to changing conditions and market demands.
The AVA's proximity to major Washington markets (Seattle, Portland) provides access to direct-to-consumer sales channels, while the quality of wines has attracted attention from sommeliers and wine programs in major metropolitan areas nationwide. As the oldest vines in the region reach 40+ years of age, wines show increasing complexity and depth that distinguish them in competitive markets.
Challenges ahead include succession planning as founding generation winemakers age, water rights and availability in an arid climate facing uncertainty, labor availability for agricultural operations, and competition from expanding wine regions worldwide. However, the distinctive terroir, proven track record of quality, and passionate community of producers position Rattlesnake Hills well for continued growth and recognition as one of Washington State's premier viticultural areas.