Upper Lake Valley AVA


Upper Lake Valley is an American Viticultural Area in northern Lake County, California located adjacent to the northern shoreline of Clear Lake. The appellation was established as the nation's 266th, the state's 146th and the county's ninth AVA on June 3, 2022, by the Alcohol and Tobacco Tax and Trade Bureau, Treasury after reviewing the petition submitted by Terry Dereniuk, on behalf of the Growers of Upper Lake Valley, proposing a viticultural area named "Upper Lake Valley."
The AVA lies within the established multi-county North Coast AVA and the established Clear Lake AVA. Upper Lake Valley encompasses approximately and, at the outset, contained 16 commercial vineyards cultivating approximately with only one bonded winery, Nice Wine Co., that was acquired in 2018 by Shannon Family of Wines. At the time the petition was submitted, at least one additional vineyard was planned.
Upper Lake Valley is elevated between above sea level in a series of valleys north of the unincorporated towns of Upper Lake and south of the Mendocino National Forest, and a stretch of Clear Lake's north shore extends from Upper Lake in the west to the unincorporated community of Nice to the east.
The Elk Mountain Valley appellation was originally proposed, but after consultation with the TTB, it was abandoned in 2018 favoring the Upper Lake Valley petition.
The Clear Lake AVA boundaries were slightly modified to fully encompass the Upper Lake Valley appellation that lies in the Upper Lake Groundwater Basin on four water-bearing formations: Quaternary alluvium, Pleistocene terrace deposits, Pleistocene lake and floodplain deposits, and Plio-Pleistocene cache creek. The petition mentions that the basin "contains high levels of ammonia, phosphorus, chloride, iron, boron, and manganese." Fifty-six percent of the area are made out of loam soil variations: Millsholm–Skyhigh-Bressa, Still–Lupoyoma, and Tulelake–Fluvaquentic–Haplawuolls. Constant, gentle winds keep grapes and leaf canopies cool and dry, and reduce the risk of mildew. Vineyards in the appellations are mostly planted on gentle slopes, favoring drainage. The plant hardiness zone range is 8b to 9b.

History

The area has been known as Upper Lake since 1875. One of the earliest viticulturists in the area was Serranus Clinton Hastings, founder of Hastings Law School, Chief Justice of the State Supreme Court and elected State Attorney General, farmed of wine grapes, including of Zinfandel, on his property located east of the town of Upper Lake in the Middle Creek Valley. In addition to vineyards, Hastings had a winery and distillery with a capacity of in production by 1886. Hastings bought more property and added it to his land holdings. "His brothers Robert Paul Hastings, Charles Foster Dio Hastings joined him in this venture and the property ran from Middle Creek to and including all of Nice proper." As noted by James Hilly in 1888, "The main feature of Upper Lake's surroundings is it peculiar adaptability for grape culture, which has been thoroughly demonstrated and test by Judge S. C. Hastings, whose experiments have resulted in the production of wine that with proper age will astonish the natives of Los Angeles and San Bernardino. There are thousands of acres of as good grape land as France, Spain, Italy or the Rhine... which are not in production at this time."
In 1884, Charles M. Hammond, along with his brother Gardiner Jr., acquired in the "East Upper Lake precinct" and subsequently planted on his Mat Tel Vineyards estate of grapes, including "Black Burgundy", Mourvèdre, Carignan, Cabernet Sauvignon, Zinfandel, "Sauvignon Vert" and Sémillon. Hammond had previously worked for Gustave Niebaum as a vineyard hand in Napa Valley for about a year. His brother Gardiner G. Hammond Jr. sold his share in 1885 to viticulturist and orchardist William O. Edmonds who grew Franken Riesling, Golden Chasselas, Muscat, and a few of the old Mission varieties. Charles Hammond's winery and distillery reportedly operated until 1915.
By 1911, there was a very active growers association representing this area. They mobilized in 1912 to fight a county-wide dry ordinance. With the advent of Prohibition in 1919, Lake County vineyards were uprooted, abandoned or replanted with orchards, notably walnuts, which currently remains a key crop in the area.
In the mid-1960's winegrapes were again planted in Lake County. The first vineyards in the Upper Lake Valley area were planted in the 1970s. According to long time grower Larry Rogers, in the early 1970s there were several pear ranchers who were searching for a diversified crop, and decided to plant test blocks of wine grapes, as historically the first agricultural product were world class wines at the end of the 19th century from the Upper Lake Valley area. Larry said he decided to plant Cabernet Sauvignon wine grapes upon recommendation from John Parducci, a large, successful vintner in Mendocino County. In Upper Lake a parcel was doubled­ planted with pears to make a hedge row and thus freeing up land to plant the wine grapes. There was a good market for the wine grapes so more vineyards were planted with success. Over the years it was discovered that the white wine grapes were better suited for the area, due to micro­climate and soil type. Sauvignon Blanc is the premier wine-grape grown in the Upper Lake Valley area, although several other varietals are grown successfully. When the Upper Lake petition was submitted, there were 16 winegrowers in the area cultivating. One of the largest vineyards in the area is the organically farmed Elk Mountain Vineyard, planted with of Sauvignon Blanc as well as one acre of Portuguese varieties.

Terroir

Topography

Upper Lake Valley was selected as the name for the appellation to reflect its topography that encompasses a series of valleys, along with their surrounding hillsides, that run in a north-northeasterly direction from the shores of Clear Lake. The northern boundary is generally concurrent with the northern boundary of the established Clear Lake AVA and separates the AVA from the higher, rugged elevations of the Mendocino National Forest. The eastern boundary follows the elevation contour and also separates the AVA from the Mendocino National Forest. The southern boundary follows the northern shore of Clear Lake. A portion of the western boundary follows a series of roads and the elevation contour to separate the AVA from the higher terrain of the Mayacamas Mountains. The remainder of the western boundary is a
straight line between points that is concurrent with the established Clear
Lake AVA boundary and also separates the AVA from the Mayacamas Mountains. The distinguishing features of the Upper Lake Valley are its geology and hydrogeology, soils, and climate.

Geology

Upper Lake Valley AVA has four identified water-bearing formations: Quaternary alluvium; Pleistocene terrace deposits; Pleistocene lake and floodplain deposits; and Plio-Pleistocene cache creek. These formations make up the Upper Lake Groundwater Basin, which covers the majority of the AVA. The petition states that groundwater levels within the Upper Lake Groundwater Basin are generally within of the surface and fluctuate between lower in the fall. Lowering of water levels during dry months is not excessive and is balanced by rapid recovery of water level elevations during the wet months. The groundwater of the Upper Lake Groundwater Basin has high levels of iron, manganese, and calcium and low levels of boron and dissolved solids.
The petition states that although the high levels of iron and manganese may clog irrigation equipment, the high levels of calcium and low levels of boron and dissolved solids are beneficial to grapevine growth. The Gravelly Valley Groundwater Basin lies to the north of the Upper Lake Valley AVA, within the Mendocino National Forest. The petition states that no additional information was available about the hydrogeology of this basin. To the east of the AVA is the High Valley Groundwater Basin, which is characterized by rocks of the Jurassic–Cretaceous Franciscan Formation and Quaternary Holocene volcanics. The groundwater contains high levels of ammonia, phosphorus, chloride, iron, boron, and manganese. The springtime groundwater level is below the surface, with the summer drawdown below the spring level.
Clear Lake is to the immediate south of the AVA, while the Big Valley Groundwater Basin is farther south. The prominent groundwater formations in the Big Valley
Groundwater Basin are Quaternary Alluvium and Upper Pliocene to Lower Pliocene Volcanic Ash Deposit. Groundwater levels in the northern portion of the Big Valley Groundwater Basin are usually below the surface and decrease during the summer. In the uplands of the basin, the depth to water in the spring is much deeper, ranging from below the surface and dropping an additional over the summer. Boron is an impairment in the water in some parts of the basin. At levels of 2 mg/l or above, Boron is toxic to most plants. To the west of the AVA is the Scotts Valley Groundwater Basin, which consists of rocks from the Jurassic–Cretaceous Franciscan Formation. Depth to water in the spring is below the surface on the average, with summer drawdown ranging from below spring levels depending on location across the basin. Boron, iron, and manganese are impairments of groundwater in this basin.

Climate

Upper Lake Valley AVA is characterized by high annual rainfall amounts, a relatively short frost-free period, low-speed but frequent winds, and low median growing degree accumulations. Annual predicted rainfall amounts within the Upper Lake Groundwater Basin, where the AVA is located, range from, which provides sufficient hydration for grapevines. To the east, west and south of the AVA, annual predicted rainfall amounts are lower, while in the region to the north, the annual predicted rainfall is approximately. The AVA has a median of 202 frost-free days per year. The median, minimum, and maximum frost-free periods within the AVA are substantially shorter than those of the established AVAs to the east, southeast, and west. The median and maximum frost-free periods in the AVA are longer than their counterparts in most AVAs to the south of the AVA, with the exception of the established Red Hills Lake County AVA. The number of frost-free days in the region to the north of the AVA was not available. Late frosts can damage new vine growth and early frosts can impact the ability of grapes to reach a desirable sugar level. The median GDD accumulation in the Upper Lake Valley AVA is 3,158, while the maximum is 3,434 and the minimum is 2,809. According to the petition, GDD accumulations within the AVA are suitable for growing a variety of grapes, including Sauvignon Blanc. The median GDD accumulation for the AVA is substantially smaller than those of established AVAs to the east, southeast, south, and west. The maximum GDD accumulation in the AVA is less than the maximum GDD accumulation in each of these established AVAs, with the exception of Benmore Valley AVA to the west and Big Valley District–Lake County AVA to the south. The minimum GDD accumulation in the AVA is lower than those of established AVAs to the east, southeast, south, and west. GDD data was not provided for the region to the north of the AVA. Within the AVA, wind speeds between account for 82.88 percent of the daytime wind speeds and 88.86 percent of nighttime wind speeds. Winds with speeds below, defined as "calm," occurred only 2.23 percent of the time during daytime hours and 3.04 percent of the time during nighttime hours. Wind speeds greater than were not recorded within the AVA. The petition states that constant, gentle winds keep grapes and leaf canopies cool and dry, and reduce the risk of mildew. According to the petition, a larger percentage of wind speeds in three established AVAs to the southeast and south of the AVA are less than, and in two of these AVAs, winds with speeds exceeding were recorded. Wind speed data was not available for the regions to the north and west of the AVA.
The petition also requested the expansion of the Clear Lake AVA boundary so that the entire Upper Lake Valley would be contained within it. The petition noted that the expansion area, located in the northern portion of Scotts Valley along Scotts Creek, has elevations within the range of those found elsewhere in the Clear Lake AVA where its vineyards are elevated between. For comparison, the expansion petition notes that the vineyard within the expansion area sits at. The expansion petition also included a map of the Clear Lake watershed, which was described as having an important effect on the climate of the Clear Lake AVA. The expansion petition notes that the map includes all of Scotts Valley, including the expansion area, in the Clear Lake watershed. Finally, the climate of the Clear Lake AVA places it in Winkler Regions II and III. The expansion petition notes that annual GDD accumulations in the expansion area range from, which also places the expansion area in Winkler Regions II and III.