Mendocino County AVAs

Mendocino County is an appellation that designates wine made from grapes grown mostly in Mendocino County. The region is part of the larger North Coast AVA and one of California's largest and most climatically diverse wine growing regions. 

Mendocino County is one of the northernmost commercial wine grape regions in the state with two distinct climate zones separated by the Mendocino Range. Ten specific American Viticultural Areas have been designated within Mendocino County. 

Mendocino is one of the leading wine growing regions for organically produced wine grapes. Nearly 25% of the acreage in Mendocino County is grown organically. In 2004, the residents of the county voted to become the first GMO-free county in the United States in an initiative that was supported by many of the county's largest wineries. The county's widespread focus on organic viticulture has inspired journalists to describe it as "California's organic wine Mecca"

Anderson Valley AVA

Established as an AVA on August 17, 1983.  The Anderson Valley AVA is centered on the Anderson Valley in Mendocino County and lies at the very northern end of California's prime winegrowing area, approximately 100 miles north of downtown San Francisco.  It is approximately a mile wide and 16 miles long, covering approximately 57,600 acres, from the town of Boonville in the south to the northernmost town of Navarro.

Cutting laterally through the coastal range rather than lying between ridges, the west or “deep end” of the Anderson Valley is only a few miles from the cold Pacific Ocean, while the town of Boonville is some 20 miles to the east. Such unique geography results in a wide diurnal range, with daily high and low temperatures occasionally diverging 40 or 50 degrees.  The valley often has long Indian summers.

The northern section of the Anderson valley is located 10 miles from the Pacific Ocean. Narrow and low lying, the valley is perfectly positioned and shaped to funnel ocean breezes and fog in from the Pacific coast. It is amongst the coolest of California's wine regions. Rain is also plentiful and concentrated to the cooler months of November through to March.

The unique combination of geographical and climatic conditions found in the northwestern end of the valley has resulted in the predominance of mostly cool climate varieties in sharp contrast to those more favored in the warmer climes to the southeast.  The valley's southern half follows Anderson Creek between Boonville and Philo. It is around 20 miles (32km) from the coast and consequently is warmer than the northwestern tip,

The Anderson Valley AVA is known primarily for its Pinot Noir and sparkling wine production and now ranks with the top Pinot Noir regions in North America.  The local climate enables Pinot Noir growers to keep acid development in line with sugar and flavor formation through long, warm Indian summers.  Anderson Valley's Pinot Noir has an uncomplicated and unique style. The Anderson Valley AVA has several methode champenoise sparkling wine houses and as such has a concentration of high quality sparkling wines. 

The long warm Indian summer also allows varieties like Cabernet Sauvignon, Merlot, Zinfandel, Syrah and Petite Syrah to ripen. Indeed, there are a small number of Zinfandel vines that are more than 100 years old – some of the oldest in the US. These still produce outstanding, concentrated wines today, but in a lighter, finer style than is traditionally associated with this robust red variety.

This climate also makes for superb Gewurztraminer and Riesling. In eastern and ridge-top sites there is plenty of warmth to ripen Chardonnay, Sauvignon Blanc and Pinot Gris.  Anderson Valley celebrates this significance with two annual wine festivals dedicated to its four key grape varieties: the International Alsace Varietals Festival (where locally produced Riesling and Gewurztraminer wines are showcased), and the Anderson Valley Pinot Noir Festival.

Cole Ranch AVA

Establishes as an AVA on April 14, 1983.  The Cole Ranch AVA is located in Mendocino County and at just 60 acres has the distinction of being North America’s smallest appellation. The AVA is located between the Russian River and Anderson Valley.  The Cole Ranch AVA can be found tucked away among the hills, just south of Ukiah, in a small valley just three miles from where the Russian River cuts a path through Mendocino County before flowing south into the Russian River Valley AVA.  Cole Ranch is located within three larger appellations - Mendocino AVA, Mendocino County, and the North Coast AVA.

At elevations of 1,400 to 1,600 feet, the vines benefit from a mesoclimate that is cooler and wetter than surrounding wine-producing areas. Indeed, the relatively high elevations ensure that the evenings are significantly colder in Cole Ranch, giving the grapes time to cool off overnight during the growing season and thereby preserving the grapes' vital acidity.  The surrounding hills offer shade in the early morning and late afternoon, limiting the amount of sunlight that reaches the vines. These two factors slow the ripening period significantly, with harvest sometimes coming up to a month later than in the surrounding Mendocino AVA.

Despite its small size, Cole Ranch is highly regarded for its white wines made from Riesling, as well as reds produced from Cabernet Sauvignon, Merlot and Pinot Noir.  All planted land in the appellation is owned by one party. Grapes are sold to several wineries. 

Covelo AVA

Established as an AVA on February 15, 2006.  The Covelo AVA is an unusual and rather remote AVA located in northern Mendocino County, although it is not part of the North Coast AVA as it lies further north than the area that is covered by the North Coast AVA. The appellation is located 45 miles north of Ukiah and includes the areas of Round and Williams Valleys. The bowl shaped basin of Round Valley is distinctly different from the long, narrow valleys more commonly found in Mendocino County.

Unlike other areas in the California wine country, Covelo has a continental climate with the high peaks surrounding the valley shielding it from the influence of the Pacific Ocean. The growing season here is one of the shortest in Mendocino County and the area experiences one of the widest diurnal temperature variation in the region.  The high peaks surrounding the region effectively block any coastal influence, providing the Covelo AVA with this continental climate.  Hot, dry summers give way rapidly to the kind of cold winters more often associated with areas much further inland.

The area is relatively flat terrain built upon deep loam soil layers, the valley floor sits at 1230ft elevation.  These deep, loamy soils of Covelo are challenging for viticulture. High in nutrients and relatively free draining, these soils promote healthy, prolific vine growth, creating the need for rigorous vineyard management.  Crop thinning and leaf plucking are just two of the techniques used here to reduce yield sizes and consequently increase fruit quality.

The growing season here is shorter than other Mendocino growing areas such as Anderson Valley and the Yorkville Highlands, but the warmer daytime temperatures provide optimum opportunity for ripening.  The reduced growing season here is easily the most distinguishing characteristic of the AVA. While there are obvious drawbacks to this, including a frost risk, the cold winter temperatures protect Covelo from Pierce's disease – a vine-killing bacterial disease.

The region only has 12 acres under vine, and the AVA title was granted with a mere 2 acres planted to vineyards at the time on the basis of the region's potential – the conditions here were too unusual to ignore – experimentation continues into which grape varieties will thrive best in the area's terroir.

Dos Rios AVA

Established as an AVA on October 13, 2005.  Dos Rios is a small AVA situated 40 miles (65km) north of Ukiah in northern Mendocino County. The Dos Rios AVA is not actually in the North Coast AVA, as it lies further north than the area that is covered by the North Coast AVA.  However the Dos Rios AVA is still located entirely in northern Mendocino County. The appellation is located near the confluence of the Eel River and the Middle Fork of the Eel River, and the areas is also renowned for its white water rafting.  Dos Rios lies to the southwest of Covelo AVA. 

Dos Rios AVA has a transitional climate - a unique combination of maritime and continental characteristics, due to the significant cooling effects of the Pacific Ocean.  The location would have a warm climate if not for the constant breezes from the Pacific Ocean.

The soil in Dos Rios AVA is more infertile than other regions in the county. Soils here are very rocky, slopes are steep and the growing conditions in this region are quite different from those in the rest of Mendocino County.

The vineyards are located on steep, infertile slopes that warm up in the hot summer sunshine and retain their heat in the cold nights, thanks to their high stone content.

The Dos Rios AVA produces wines from red grape varieties including Cabernet Franc, Zinfandel, Cabernet Sauvignon, Merlot, Syrah, Petit Verdot and Charbono.

McDowell Valley AVA

Established as an AVA on December 3, 1981.  The McDowell Valley AVA is located in southeastern Mendocino County, near Hopland. It is a small AVA, it spans just 540 acres on a sloping bench about 3 miles east of the town of Hopland at elevations as high as 1,000 feet above sea level that overlook the Russian River to the west.

McDowell Valley is slightly cooler than the surrounding areas of Mendocino County.  The river provides a temperature-moderating and cooling influence to vines. In combination with the warming effect provided by the nearby mountains, the Mediterranean climate here is well-suited to viticulture. 

The valley enjoys a cooler climate than surrounding areas ideal for the cultivation of Rhône grape varieties and is particularly celebrated for the quality of its Syrah. McDowell Valley has some of the oldest Syrah vines in California. Grenache and Zinfandel are particularly well-suited to the terroir of the AVA and popular white-grape varieties include Marsanne and Viognier, which complement the roster of big flavorful reds.

Mendocino Ridge AVA

Established as an AVA on October 26, 1997.  The Mendocino Ridge AVA is a coastal, cool climate and high altitude area located entirely within the coastal zone of Mendocino County. The boundaries of the AVA encompass the coastal ridges adjacent to the Pacific Ocean that reach inland toward the Anderson Valley. Roughly 36 miles of the southernmost portion of the Mendocino Coast make up the western boundary of the AVA, with the Sonoma County line as the southern boundary, the Navarro River as the northern boundary and Anderson Valley as the inland boundary running northwest–southeast. The Mendocino Ridge AVA "is essentially a northern extension of the true Sonoma Coast viticultural area." However, the Mendocino Ridge AVA designation is unique in that it is limited by elevation, reserved only for vineyards at or above 1200 feet.

Mendocino Ridge is the only non-contiguous AVA in the United States; all others are contiguous landmasses with all vineyards inside the boundaries designated as part of the AVA, whereas Mendocino Ridge in comparison only includes the higher altitude growing sites. There are 262,400 acres within the outer boundaries of the Mendocino Ridge viticultural area, but the actual viticultural area encompasses only 87,466 acres which lie above 1,200 feet elevation. Of these approximately 1,500 to 2,000 acres of the ridge tops are suitable for vineyards. The side-slopes are very steep (often above 70%) and covered with timber, making them unfit for planting. 

This is why the Mendocino Ridge AVA has been nicknamed "Islands in the Sky®," because the vineyards sitting at 1200 feet or higher are often perched above thick fog moving inland from the Pacific Ocean blanketing the coast and the valleys between the ridge tops, making the tips of the mountains look like islands protruding from a sea of fog.

The average high temperature is 75.9 °F and the average low temperature is 49.4 °F. In the Mendocino Ridge AVA the diurnal variation during the growing season is significantly less than the Anderson Valley (20 degrees versus 40-50 degrees in Anderson Valley), and daytime high temperatures are often 10 degrees cooler than in the Anderson Valley." The soil composition is of the "timber" type, shallow and with good drainage due to the ridge top locations. Average annual rainfall average is 58 inches, leaving sufficient groundwater to dry farm vineyards.

Estimates of planted acres range from 233 to 410, which accounts for about 0.3% of the total area. These planted acres are scattered among 16 remote vineyards.

Mendocino Ridge has some of the oldest vineyards in the region. Italian immigrants in the late 1800s planted on Greenwood Ridge and surrounding areas, preferring Zinfandel which remains a popular varietal in the AVA, although Pinot Noir has become the most common grape in the region since the 1990s. Mendocino Ridge AVA is still recognized for producing some of the very best, most distinctive Zinfandels anywhere.

Other plantings (ordered by decreasing representation in total acres) include Chardonnay, Syrah, Merlot, Riesling, Sauvignon Blanc, Primitivo, Petite Syrah, Cabernet Sauvignon, and Grüner Veltliner. Much of the non-planted land is covered by Redwood and Douglas Fir trees.

Potter Valley AVA

Established as an AVA on October 12, 1983.  The Potter Valley AVA is located in northern Mendocino County, with its center in the town of Potter Valley. This appellation is located to the east of the Redwood Valley AVA and sits at an elevation approximately 200 feet higher than the surrounding areas. 

The appellation encompasses a valley that runs north to south for approximately six miles, planted to a little more than 1000 acres of vines. The AVA is separated from the Lake County AVA by the Mayacama mountain range in the east, while the Redwood Valley AVA makes up the area's western border.

Great day-night temperature variations separate Potter Valley from other growing areas in Mendocino. Mid-day in this inland valley can be truly hot, but nighttime temperatures plummet.  This significant diurnal temperature variation is more pronounced than in other parts of Mendocino (with the exception of Mendocino Ridge). These climatic conditions result in a long growing season and good retention of acidity. 

One of the other main features of Potter Valley is its soils. These are generally bedrock, covered by an alluvial layer of silt, sand and clay. The high water table and rainfall raise humidity in some areas, increasing the potential for noble rot (Botrytis cinerea) to develop – making it possible to produce dessert wines from Riesling, Sémillon and Sauvignon Blanc.

Potter Valley is in the northeastern reaches of the Mendocino AVA in California. The appellation's relatively high elevations and subsequent cool climate make it suitable for the production of crisp, balanced wines from Riesling, Sauvignon Blanc and Chardonnay, as well as Pinot Noir and Zinfandel, developing strong but refined character.

There are only a few wineries based in Potter Valley and the majority of wines that are labelled under the Potter Valley AVA are produced by wineries in other Californian regions. 

Redwood Valley AVA

Established as an AVA on December 22, 1996.  The Redwood Valley AVA is located in Mendocino County.  Perhaps unsurprisingly, the valley derives its name from the redwood trees that dominate the landscape.  The valley sits at an elevation that is 200 feet higher than the surrounding area.  The hills surrounding Redwood Valley are home to the headwaters of the Russian River, which runs through the valley itself. Despite this, the Redwood Valley is quite distinct from the Russian River Valley AVA in Sonoma, the boundaries of which do not start for another 50 miles along the river.

The terroir of the valley is characterized by its high elevation. Sitting roughly at an elevation of 800 feet, Redwood Valley enjoys warm days with intense sunlight, but the nights are cold as a result of the cool breezes and fog that seep from the Pacific Ocean through a gap in the Coastal Range. This diurnal temperature variation ensures a longer ripening period in which the grapes can develop ripe fruit characters while retaining acidity.

The red, rocky soils are one of the most distinguishing features of the terroir. They are free-draining and rich in iron, and their clay content means they have moderate water retention capabilities. This is ideal for the production of premium grapes – vines that are planted on thin, dry soils grow deep root systems to access the water stored below. This leads to healthy vines that produce small, concentrated grapes with a high skin-to-juice ratio.

Some of the first vineyards were planted in Redwood Valley in the 1880s by Italian and Greek immigrants, although viticulture remained on a small scale up until the 1950s.  The arrival of a few large wineries and an increase in planting then led to an upsurge in grape growing in the valley – at one point, around half of all vines planted in Mendocino could be found in Redwood Valley.

The appellation is best known for its red wines, particularly those produced from Cabernet Sauvignon, Petite Syrah, and Zinfandel.  A substantial number of wineries in Redwood Valley practice organic agricultural techniques. Along with the rich, full-bodied red wines, the AVA is also home to examples of Chardonnay and Sauvignon Blanc.

Yorkville Highlands AVA

Established as an AVA on April 6, 1998.  The Yorkville Highlands AVA is located in southern Mendocino County. The Yorkville Highlands separate Sonoma County's Alexander Valley AVA from Mendocino County's Anderson Valley AVA.

The Yorkville Highlands AVA starts just five miles west of Cloverdale on Highway 128. The main distinguishing factor of the AVA is its elevation.  The Yorkville Highlands AVA appellation consists of approximately 40,000 acres straddling Highway 128 between the Alexander Valley to the southeast and the Anderson Valley to the northwest.  The vineyards are planted between 850 and 2,500 ft.

The area is a continuous string of high benches and land troughs bordered by even higher ridges with Highway 128 running down the middle. The U.S.G.S. topographic maps show the area is a valley, with Highway 128 and the Rancheria and Dry Creeks running along the northwest-southeast axis. This center line of the area is the lowest part, at approximately 850 feet, and the highest, in the area near the northern boundary, is over 3,000 feet.

The climate of the AVA has days warmer than Anderson Valley but cooler than Hopland. The nights are cooler than both Anderson Valley and Hopland. This means many grape varieties can be grown in this area but will have a long ripening period which will greatly enhance fruit flavors and quality. Dramatic diurnal shifts in temperature of 40º to 50º can be quite common in the summer and sometimes in the winter. This can be key as the nighttime cooling intensifies polyphenol compounds (flavors), preserves acidity, and tends to produce smaller berries during the growing season.

The climate in the Yorkville Highlands is influenced by marine air well over 50 percent of the time. Almost every morning during the growing season, the moist marine fog is found on the high benchlands and land troughs, which connect the cooler Anderson Valley with the much warmer Alexander Valley. The trees on these bench lands are draped with the moss from this ocean air invasion and cooler climatic condition. Average annual rainfall within the Yorkville Highlands area is about 25% higher than the Anderson Valley, to the northwest. 

The soil in the Yorkville Highlands is rocky with a high gravel content, which provides excellent drainage. The area differs from the Anderson Valley or Hopland. The soils are thinner than Hopland but more fertile and varied than Anderson Valley. In the Yorkville Highlands they are rocky hill soils characterized by gravel and old brittle rock. These generally thin soils found on the high benches and land troughs of the area stand in stark contrast to the generally very loamy clay soils found in the valleys and bottom lands dominating the neighboring approved viticultural areas.

Its largest plantings are in order: Cabernet Sauvignon, Syrah, Pinot Noir, and Merlot. Of the 414 total acres planted, 83% are red varietals.

The additional AVAs in Mendocino County that are not part of the main Mendocino AVA, or are only partly in the county are:

Eagle Peak Mendocino County AVA

Established as an AVA on October 8, 2014.  Eagle Peak Mendocino County is located in Mendocino County. It lies within the North Coast AVA and takes its name from the nearby Eagle Peak summit covering the mountainous area situated in the California Coastal Range just west of the Redwood Valley AVA and east of the V-shaped Mendocino AVA. The AVA is situated 125 miles north of San Francisco and encompasses nearly 21,000 acres of mountainous terrain, it is an inland AVA with elevations from 700 to 3,320 feet.  It straddles U.S. Highway 101 between the towns of Ukiah and Willits.

The AVA consists of steep rugged terrain, high elevations, moderate temperatures, cooling winds, and well-drained mountain soils.  It is ideally situated in a climatic transition zone between the cool, wet climate of the Pacific coast and the warm, dry inland valleys of Mendocino County.  It experiences more seasonal temperature variation than coastal AVAs with less fog. Persistent breezes of 5-10 MPH travel from the ocean through the Big River airflow corridor.

The soils are well-drained since water doesn't stick around due to the slopes and shallow root depths because of hard subsoil, There is enough water-holding capacity to keep vines healthy from dormancy through fruit set, however, some irrigation is required to usher the vines through to harvest.

The AVA encompasses approximately 120 acres of cultivated vines.  Pinot Noir grows best in Eagle Peak, as the temperature tends to be cooler than the inland valleys, making balanced, lush red wines that are quite distinct from those made further south.

Pine Mountain-Cloverdale Peak AVA

Established as an AVA on 26 October, 2011.  The Pine Mountain-Cloverdale Peak AVA is in Sonoma County and also in Mendocino County. It is located at the top of Pine Mountain, at the Northern end of the Mayacamas Range, which separates the Napa and Sonoma growing regions. The AVA, is one of the highest grape growing regions in California, which rises from 1,600 feet at its lowest point to 3,000 feet at the mountain’s peak, has grapes growing primarily at 1,800 feet and higher.

The very high elevation of the mountain affects fog cover, hours of daylight, daytime and nighttime temperatures, rainfall, and wind — virtually every climatic element influencing wine grape production.

On average, there is a twelve degree drop in temperature between the valley floor and the center of the Pine Mountain-Cloverdale Peak AVA. Despite the cooler days, growers on the mountain paradoxically experience relatively warmer night time temperatures, the result of cooler air dropping into the valley, displacing warm air upwards. At 1600 feet, the valley also sits well above the fog that collects in the mornings and evenings down in the valley, giving it three to four more hours of sunlight a day. This unique microclimate creates an altered growing season for Pine Mountain growers, with bud break occurring two to three weeks after vineyards on the valley floor.

The Pine Mountain-Cloverdale Peak Appellation has rocky volcanic soils of steep hillsides and ancient alluvial fans. Soils are shallow to moderately deep fractured shale and sandstone, very well drained through gravels. In general, soils are less than 3 feet deep, with over 50% at 12 inches or less.  The mountain is home to a number of natural springs, which were bottled and sold as a mineral water for over 50 years. Pine Mountain Spring water ceased production in the 1950s.

The Pine Mountain-Cloverdale Peak AVA is one of the highest and most remote winegrowing sub-regions in Sonoma County. Of its 4,600 acres, just 230 acres are planted with grapevines.  The long season and high sunlight exposure here favor red wine grapes; Cabernet Sauvignon is the undisputed sovereign of the mountain, accounting for some 80 percent of vineyard acres, while Merlot and Malbec are a distant second and third. Alternative red varieties include Sangiovese and Lagrein, and the occasional white variety, such as Muscat or Riesling, is grown here, too.