| SPRING MOUNTAIN VITICULTURAL AREA PETITION
This petition for establishment of the Spring Mountain viticultural area was developed with sensitivity toward both the local community and the world beyond that community. The Napa Valley’s significance as a wine region demands that care be taken to safeguard the region’s integrity. This petition reflects such care, not only for Napa Valley as a whole, but also for viticultural areas already established within the valley, and those that will be established in the future. This petition likewise takes into consideration a broader audience; the millions of consumers whose interests the Bureau of Alcohol, Tobacco and Firearms and the Department of Treasury represent. The establishment of Spring Mountain as a viticultural area will aid those consumers by providing more precise information with which to make wine buying decisions.
1. EVIDENCE THAT THE NAME OF THE AREA IS LOCALLY OR NATIONALLY KNOWN. a. Name Derivation Spring Mountain is located in Napa County, California, on the eastern slope of the Mayacamas Mountains that separate Napa Valley from Sonoma Valley and the Santa Rosa Plain. The proposed Spring Mountain viticultural area contains approximately 8,600 acres, of which approximately 800 acres are planted to vineyards. Thirteen wineries are currently active within the proposed viticultural area. The book California Place Names, under the entry for “Spring” states, “Most of the places that include the word were applied because of the presence of an active spring.” Such is clearly the case at Spring Mountain. The region has numerous springs, and is
drained by several small streams. Because of the abundance of water in Spring Mountain, the nearby town of St. Helena used reservoirs located in the region as its primary sources of drinking water from 1878 to the 1920s. Despite the nomenclature in the name, Spring Mountain is not – and was not – the name of a peak or prominent point in the region. From the beginning, Spring Mountain has always been used in a regional context. The degree to which the name Spring Mountain is linked to the region is reflected in the name of the school that educated children in the area from the 1870s to the 1930s, Spring Mountain School, and in the name of the principal road through the area, Spring Mountain Road. The exact date when the name Spring Mountain was applied to the region is not certain. The earliest print use of Spring Mountain in reference to the region appears in an article in the St. Helena Star on December 7, 1877 [Exhibit 1].
Spring Mountain was among the first locations in the Napa Valley to receive recognition as a wine grape region. Beginning with the earliest article to mention Spring Mountain on December 7, 1877 [Exhibit 1], the St. Helena Star frequently mentioned viticultural activities in the region. The early 1880s offer several examples of such coverage, including the total tonnage produced in the region in 1879 [Exhibit 2] and a new property owner’s plans for vineyard planting in 1882 [Exhibit 3]. In 1888, Spring Mountain received a measure of recognition in California with publication of the Annual Report of State Viticultural Commissioners for 1887. On the page listing varieties of grapes planted in Napa County, Spring Mountain was one of only twelve locations listed [Exhibit 4]. Articles on Spring Mountain and the region’s developing wine industry continued to appear in local newspapers in the 1890s [Exhibits 5 and 6]. Despite having vineyards that weathered both Prohibition and the Great Depression, the region received scant coverage during the first half of the 20th century, a reflection of the general decline of the wine industry in California during that era. With the planting of new vineyards and the establishment of new wineries beginning in the 1950s, Spring Mountain has gained a national reputation for the quality of its grapes and wines. The willingness of wineries to publicize their location in Spring Mountain in the Napa Valley Wine Auction catalog [Exhibits 7, 8, 9 and 10], the use of Spring Mountain as an appellation of origin on Cabernet Sauvignon wines produced by Ritchie Creek Vineyards in the late 1970s and early 1980s [Exhibit 11] and the use of the appellation on Cabernet Sauvignon and Petite Sirah wines produced by Ridge Vineyards [Exhibits 12 and 13] have highlighted the premium quality and distinctive character of the region’s grapes and wines to an appreciative and discerning public. The reputation that the proposed Spring Mountain viticultural area has developed nationally can also be seen in the writings of such noted wine authorities as Charles Olken and Earl Singer [Exhibit 14], James Laube [Exhibit 15], William Massee [Exhibit 16], Hugh Johnson [Exhibit 17] and Bruce Cass [Exhibit 18]. In virtually every case, these writers refer to Spring Mountain as a distinctive viticultural area within the Napa Valley, and emphasize the distinctive quality of the grapes produced in its hillside vineyards. # # # 2. HISTORICAL OR CURRENT EVIDENCE THAT THE BOUNDARIES OF THE PROPOSED VITICULTURAL AREA ARE AS SPECIFIED IN THE APPLICATION. The proposed Spring Mountain viticultural area encompasses approximately 8,600 acres of land on the eastern slope of the Mayacamas Mountains, west of the town of St. Helena, California. Approximately 800 acres within the proposed viticultural area are planted to vineyards and a significant portion of the grape production from these vineyards are utilized by the 13 wineries now established in the region [Exhibit 19, which shows the location of current vineyards and wineries]. Although vines may have been planted in the region as early as 1867, the first documented vineyard planting in the proposed Spring Mountain viticultural area took place around 1874, when Charles Lemme established a 25 acre vineyard just south of York Creek. According to a December 7, 1877 St. Helena Star [Exhibit 1], Mr. Lemme had built a cellar for winemaking the previous year, and produced 5,000 gallons of wine in both the previous and current vintage. By 1892, Charles Lemme’s La Perla Vineyard had grown to 80 acres. Published reports reveal steady growth in both vineyard acreage and wineries within the proposed viticultural area from 1880 to 1905. Jacob and Frederick Beringer, whose winery near St. Helena was then among the largest in Napa Valley, planted a 16 acre vineyard in 1882 on land they owned just east of Charles Lemme and expanded their Spring Mountain vineyard to 85 acres by 1887 [Exhibits 20 and 21]. Tiburcio Parrott purchased 800 acres on Spring Mountain, east and south of Beringer and Lemme, in 1885. By 1893, Parrott had planted a vineyard of 120 acres on the property he called Miravalle and had built an underground wine cellar with storage capacity for 60,000 gallons [Exhibit 22]. Fortune Chevalier and George Chevalier (father and son) planted 25 acres of grapes in the late 1880s and constructed a stone winery (Chateau Chevalier) with a capacity of 50,000 gallons in 1891 on land just west of the Beringer Brothers’ property [Exhibit 6]. Farther west, near the top of Spring Mountain Road, Carl Conradi 1. Annual Report of the Board of State Viticultural Commissioners for 1892-93 (Sacramento, CA: State Office, 1893) page 36. 2. Ibid, page 38. Planted 70 acres in the early 1890’s, but did not construct a winery until 1904.(3) Additional vineyards were also planted in the region during this era, though with less fanfare than the prominent names previously detailed. More than 100 acres of vineyards listed by the viticultural commissioner of Napa County in the Annual Report of the Board of State Viticultural Commissioners for 1892-93 are shown as being located in the proposed Spring Mountain viticultural area by the official map of Napa County of 1895, including those of T. Moding (22 acres), W. Sheehan (12 acres), Julia Sheehan (22 acres), M. Kilduff (25 acres), T. Traddett (10 acres) and F. Soto (14 acres) [the locations of all historical vineyards are shown in Exhibit 23]. As the commissioner’s list has proven to be incomplete, several additional vineyards in the region likely were unrecorded. Completion of the Conradi Winery in 1904 would be the last major advance in Spring Mountain’s viticultural development for many years. While local newspapers and histories did not cover the decline of grape growing and winemaking in the region between 1910 and 1946, the twin scourges of phylloxera and Prohibition clearly took their toll in Spring Mountain. Vineyards stricken by phylloxera were in many cases not replanted after Prohibition took effect in 1920, and wineries closed by Prohibition were not reopened following its repeal in 1933. Nevertheless, a few vineyards and wineries remained active during this period. Personal reminiscences from several long-time residents indicate that the Conradi Winery produced wine during Prohibition and sold it to Jewish Synagogues for religious purposes. These sources also indicate that grapes grown in Chateau Chevalier’s vineyard during Prohibition were sold to Graystone Cellars. The vineyards at both Conradi and Chateau Chevalier appear to have been abandoned soon after Prohibition’s repeal, but other original vineyards (either initially planted with resistant rootstock, or replanted to resistant rootstock) remained in production. The modern era of viticultural expansion in Spring Mountain began quietly in 1946, when Fred and Eleanor McCrea planted a small vineyard north of Mill Creek. After expanding their vineyard to 35 acres (and later to 42 acres), the McCreas built a winery and founded Stony Hill Vineyard in 1953. Stony Hill has been in production since that time, gaining an excellent reputation for Chardonnay produced from Spring Mountain grapes [Exhibit 24]. Pinot Noir produced from John Gantner’s School House Vineyard in the region also garnered a consumer following beginning in the 1950s. 3. William Heintz, Wine Country, A History of Napa Valley (Santa Barbara, CA: Capra Press, 1990) pages 275 and 276. Spring Mountain’s resurgence as a viticultural area began in earnest in the late 1960s and 1970s. The first block in the 8 acre Ritchie Creek Vineyard was planted in 1967, although the winery was not built until 1974. Lyncrest Vineyards was established in 1969 with 40 acres of vineyards. Yverdon Vineyards was founded in 1970, and planted a 10 acre vineyard (now expanded to 12 acres) that same year. Chateau Chevalier was re-established as a winery in 1973, after 60 acres of vineyards were replanted on the original vineyard site. Tribucio Parrott’s Miravalle was reopened as Spring Mountain Winery in 1976, with 25 acres of replanted vineyards. Smith-Madrone Winery was founded in 1977, after 32 acres of vineyards were planted on the site of the original vineyard planted by T. Molding in the late 1800s. Robert Keenan Winery was established in the former Conradi Winery in 1977, and now has 52 acres of estate vineyards. Newton Vineyard was established as a winery in 1979, and has since developed 100 acres of vineyards on land once part of the Parrott estate. Two large independent vineyards in the proposed viticultural area – the La Perla Vineyard and York Creek Vineyards – also gained increased recognition during this period. Spring Mountain continued to gain new vineyards and wineries in the 1980s and early 1990s. The new wineries include Cain Cellars (founded in 1982, with 87 acres of estate vineyard), Marston Vineyards (founded in 1982 on the former Lyncrest property, with 40 acres of estate vineyard), La Vieille Montagne (founded in 1983, with 10 acres of estate vineyard), Streblow Vineyards (founded in 1985, with 10 acres of estate vineyard) and Philip Togni Vineyard (founded in 1985, with 11 acres of estate vineyard). Several small vineyards were also planted in the region by independent growers [modern vineyards and wineries are shown in Exhibit 19]. While Spring Mountain has had a long history as a viticultural region, precise regional boundaries have never, until now, been established. The boundaries proposed in this petition were drawn to include all of the historic and modern vineyards and wineries associated with Spring Mountain (and detailed in this section) in the Spring Mountain viticultural area. Over the years, wines produced from grapes grown in the proposed viticultural area have established an impressive reputation for quality and distinctive personality. This reputation evolved from the growing interest on the part of the wine industry and wine consumers in specific designations of grape origin, and the subtle shadings of character and style that these vineyard locations contribute to the wine. As Connoisseur’s Guide to California Wines stated in its January-February 1977 issue, “Spring Mountain…has supported vineyard for over 100 years and is probably more responsible than any other Napa hillside for creating the mystique of “mountain grapes”.” Cabernet Sauvignon, Chardonnay and Petite Sirah from Spring Mountain have all received recognition for their singular character. To address consumer interest in the source of grapes as it pertains to the quality and character of finished wine, Ritchie Creek Vineyards, located in the proposed Spring Mountain viticultural area, used Spring Mountain as the appellation of origin of Cabernet Sauvignon wines produced from 1978 to 1980 [Exhibit 11]. In addition, Ridge Vineyards, located outside the proposed viticultural area, used its label to highlight that the grapes for particular bottlings of Cabernet Sauvignon and Petite Sirah came from Spring Mountain [Exhibits 12 and 13]. The use of Spring Mountain by these wine producers is a clear indicator of the reputation and regard the region has gained for distinctive quality. The boundaries of the proposed Spring Mountain viticultural area have been drawn with a sensitivity both for historical evidence and the geographical features that distinguish this region from those surrounding it. Care has been taken to include all the vineyard locations responsible for the region’s viticultural history, as well as those that have contributed to its reputation in recent years. Likewise, the boundaries have been drawn to respect neighboring regions with separate names, histories and geographical identities. The eastern boundary follows the 400 foot contour line for its entire length. The Bureau of Alcohol, Tobacco and Firearms has generally considered this the dividing line between the valley floor and hillside vineyards in the Napa Valley, a view stated in the final rulemaking for the Los Carneros viticultural area (4) and tacitly acknowledged in the boundaries of the Mount Veeder viticultural area (5). This boundary also accurately reflects the lowest elevation of viticultural properties historically associated with Spring Mountain. Following Ritchie Creek and the section boundary to the Napa-Sonoma county line, the northern boundary encompasses vineyards and wineries important to the region’s modern history, including Stony Hill Vineyard and Smith-Madrone Winery. This boundary marks the historic northern limit of the Spring Mountain region, and separates the region from Diamond Mountain, a vineyard area with legitimate potential for viticultural area status. 4. “Notice of Final Rulemaking, Los Carneros Viticultural Area,” Federal Register (Washington, D.C.: Government Printing Office, August 18, 1983) page 37367. 5. “Notice of Final Rulemaking, Mount Veeder Viticultural Area,” Federal Register (Washington, D.C.: Government Printing Office, January 20, 1990) page 2842. The official boundary line between Napa and Sonoma counties provides the western boundary for the proposed viticultural area. In addition to including wineries and vineyards significant to the early and modern history of the proposed viticultural area, such as Ritchie Creek Vineyards, Yverdon Vineyards and Cain Cellars, this boundary acknowledges the differences in history, climate and geography that set Spring Mountain apart from the slopes of the Mayacamas Mountains in Sonoma County. The southern boundary follows a tributary of Sulpher Creek, Sulpher Creek itself, and the 400 foot contour line. This boundary defines the historic southern limit of Spring Mountain as established by both history and viticultural activity, and also marks the southern extent of the region’s distinctive climate and soils. # # #
Introduction The proposed Spring Mountain viticultural area is distinguished by several geographical features. These features combine to create grapes and wines of distinctive quality and character. The soil, climate, and aspect responsible for the unique quality and character of Spring Mountain grapes and wines are detailed in the following two reports, and summarized at the end of this section. The soil report on the proposed Spring Mountain viticultural area was prepared by Eugene L. Begg. Mr. Begg has a Bachelor’s of Science degree in soil sciences from the University of California at Berkeley and has taken advanced studies toward a Master’s of Science degree at the University of California at Davis. From 1942 to 1990, he was a soil specialist and lecturer at the Department of Land, Air and Water Resources, University of California at Davis. He has been a member of the California Soil Survey Committee since 1974, and has reviewed new and revised soil series descriptions for the National Cooperative Soil Survey since 1970. Mr. Begg’s writings on soil and vegetation have been widely published. He has served as an expert consultant on a variety of soil matters in both regulatory hearings and legal cases. The climate overview of the proposed Spring Mountain viticultural area was prepared by Steve Newman. A member of the American Meteorological Society, Mr. Newman is meteorologist for the San Francisco Chronicle, a post he has held for more than a decade. He also serves as meteorologist for KRON Television n San Francisco, the Santa Rosa Press Democrat and the Sacramento Bee. Mr. Newman founded Earth Environment Service, a climate forecasting firm based in Santa Rosa, California, in 1983. The company’s client list includes LucasFilms, Disney Studios and the California Department of Transportation.
SOILS REPORT PROPOSED SPRING MOUNTAIN VITICULTURAL AREA
Eugene L. Begg Soils Consultant Atascadero, CA 93422 July, 1991
The proposed Spring Mountain viticultural area, west of St. Helena in Napa County, is located on the eastern slope of the Mayacamas Mountains. Approximately 8,600 acres in size, the proposed viticultural area is roughly rectangular in shape, extending south from the northern boundary along Ritchie Creek approximately five miles to slightly beyond Sulpher Creek, and east from the Napa-Sonoma county line along the summit of the Mayacamas Mountain range to the 400 foot elevation near the floor of Napa Valley. The portion of the Mayacamas Mountains in the proposed viticultural area is made up of sedimentary rocks (sandstones and shales) of Franciscan age, capped by volcanic rocks (tuffs, rhyolites and andesites) of Pliocene age laid down two to eleven million years B.P. (1). Subsequently, the region was faulted and uplifted, initiating erosion and dissection that has sculptured the area into its present landscape of deeply incised streams and prominent ridges. With partial dissection and erosion of the volcanic capping, the underlying sedimentary rocks have been exposed in various locations and subsequently weathered to form sedimentary upland soils. The general climate of the proposed Spring Mountain viticultural area is characterized by cool, wet winters and warm, dry summers, moderated by periodic ocean breezes and fog. Mean annual rainfall ranges from 35 to 40 inches. Both the seasonal and daily temperature extremes are usually moderate in this location. The small rainfall differences and moderate temperature extremes within the region are reflected in limited plant diversity. In general, the plant cover ranges from mixed shrub and shrub-hardwood communities at lower elevations to a conifer-hardwood forest of Douglas Fir, redwood, madrone, oak, laurel and maple at higher elevations and in more humid locations along creeks and on north-facing slopes. Some south-facing slopes of shallower soils have open woodland-grass areas or thin strands of shrubs and grasses. The interaction of climate, plant communities and topographic differences in the weathering of the different rock types within the proposed viticultural area has produced a wide variety of upland soils. This diversity of soils was recognized by the USDA Soil Conservation Service in their updated 1978 “Soil Survey of Napa County, California” (2) In their field mapping and classification of the soils within Napa County, they recognized fifteen soil series, twenty-seven soil types and/or phases, and one miscellaneous land type. The soil series were the Aiken, Boomer, Felta and Hambright soils from andesite and basalt; the Forward and Kidd soils from rhyolite or rhyolite tuffs; the Henneke and Montara soils from serpentine; and the Bressa, Dibble, Felton, Lodo, Maymen, Millsholm and Sobrante soils from sandstones and shales. In surveying the soils of the proposed Spring Mountain viticultural area, two elements stand out. First, Spring Mountain has only residual upland soils within its boundaries; no alluvial soils are present in the region. Second, the residual upland soils mapped in Spring Mountain are almost equally divided between those created from volcanic parent material and those created from sedimentary parent material. These two elements differentiate the proposed Spring Mountain viticultural area from surrounding regions such as the Napa Valley to the east, Diamond Mountain to the north, Mount Veeder to the south and the western slopes of the Mayacamas Mountains in Sonoma County to the west. The residual upland soils of the proposed Spring Mountain viticultural area differ markedly from the deep, alluvial soils on the floor of the Napa Valley, both in composition and derivation. The soils on the valley floor are developed on fill materials outwashed from the upland soils and rocks surrounding the valley. The soil in each alluvial fan, terrace or floodplain in the valley is a function of the soils and geology of the drainage area of each stream. The Soil Conservation Service in their mapping of the soils of Napa County (2) recognized ten alluvial soils in the valley: the Bale, Clear Lake, Cole, Coombs, Cortina, Haire, Maxwell, Perkins, Pleasanton and Yolo series. None of these alluvial soils are found on the upland slopes of the proposed Spring Mountain viticultural area. North of Spring Mountain, the segment of the Mayacamas Mountains from Diamond Mountain northward is comprised almost entirely of residual upland soils of volcanic origins. Streams downcutting the volcanic capping of the northeast of the Mayacamas Mountains in this area have not incised deeply enough to expose the underlying sedimentary rocks of the Franciscan formation. As a result, the upland sedimentary rock soils (Bressa, Dibble, Felton, Lodo, Maymen, Millsholm and Sobrante) commonly mapped in the Spring Mountain region are absent farther north, as are the two soils (Henneke and Montara) developed from serpentine. Soils developed from volcanic rock are common to both areas, but the proportion of these soils – especially Aiken and Boomer – is far greater to the north. The significant difference in soils and geology between the Spring Mountain viticultural area and the Mayacamas Mountains region to the south – including Mount Veeder – reflects the greater degree of dissection and downcutting in the latter region, which has effectively removed much of the volcanic capping and exposed extensive areas of sedimentary rocks and serpentine. Remnants of volcanic rocks remain in only a few locations in the ….. [ bad copy – not readable] …. of the Mayacamas range. Of the six residual …. Soils from volcanic rocks (Aiken, Boomer, Felta, Forward, …….. and Kidd) mapped in Spring Mountain, only one (Forward) ….in any significant acreage to the south. Six residual …… (Bressa, Dibble, Felton, Lodo, Maymen and Millsholm) from …..rocks are mapped in both areas, but the acreage and percentage of these sedimentary residual rocks is much greater in …. Southern segment of the Mayacamas Mountains, south of Spring Mountain. The Napa-Sonoma County boundary follows the drainage divide between the watersheds of the Napa River and both Sonoma Creek and Mark West Creek. The Spring Mountain viticultural area is distinguished from Sonoma County to the west by significant differences in soils, vegetation and climate. These differences are partially due to microclimate variations between the warmer, more arid southwest facing slopes of Sonoma County and the cooler, more humid easterly slopes of the proposed viticultural area in Napa County. The warmer slopes in Sonoma County have greater evapotranspiration loss of soil moisture which is reflected in shallower soils and the presence of dryer climate plant communities such as mixed shrubs or woodland-grass-shrubs. Unlike Spring Mountain, the southwest slopes of the Mayacamas Mountains in Sonoma County contain extensive areas of volcanic rockland, with large acreage of shallow, rocky soils of the Goulding and Toomes series from volcanic rocks and the Henneke soils from serpentine. (3) There are no Goulding or Toomes soils in the proposed Spring Mountain viticultural area, and areas of Henneke soil are very minor in extent. While the Bressa, Dibble, Felton, Lodo, Maymen, Millsholm and Sobrante soils (developed from sandstones and shales) are present in the Spring Mountain viticultural area, only the Maymen soil is mapped on the southwestern slopes in Sonoma County. Also absent from the Sonoma County slopes are the Aiken, Boomer, Forward, Felta and Kidd soils developed from volcanic rocks, all of which are present in the proposed viticultural area.
The Special conditions or features of the proposed Spring Mountain viticultural area which distinguish it from adjacent areas in Napa and Sonoma County are: 1. The predominance of moderately deep and deep upland soils, and the absence of alluvial soils; 2. The equal mix of upland soils derived from volcanic and sedimentary parent material; 3. The absence of volcanic rocklands and the shallow soils associated with such terrain; 4. The mixture of plant communities, including shrub-hardwood communities at lower elevations and conifer-hardwood forest at higher elevations and in more humid locations. This unique combination of soils, geology, topography and flora sets Spring Mountain apart from surrounding regions and justifies approval of the proposed Spring Mountain viticultural area. REFERENCES 1. California Department of Conservation, Division of Mines and Geology. 1982. Geologic Map of the Santa Rosa Quadrangle, Regional Geologic Map Series, Map No. 2A., maps and charts. 2. United States Department of Agriculture, Soil Conservation Service. 1978. oil Survey of Napa County, California. 104 pp., 47 map sheets, illus. 3. United States Department of Agriculture, Soil Conservation Service. 1972. Soil Survey of Sonoma County, California. 188 pp., 123 map sheets, illus.
Variations in climate in adjacent land locations are primarily the result of subtle differences in terrain and/or regional climatic influences. I found the localized effects of terrain and regional climatic influences clearly defined on Spring Mountain, resulting in distinctive microclimate within the viticultural area’s boundaries. The proposed Spring Mountain viticultural area is located on the eastern slope of the Mayacamas Mountains that separate Napa Valley from Sonoma Valley. The region is approximately 25 miles north of San Pablo Bay and 30 miles east of the Pacific Ocean. The terrain in the region consists primarily of east-facing slopes of varying steepness, ranging elevation from 400 to 2,600 feet. Spring Mountain viticultural area is classified under the Koppen Climate Classification System as having Mediterranean West Coast Climate. Mediterranean West Coast Climate is characterized by rainfall which is generally confined to the winter and early spring months which is sufficient for dry farming of various fruit crops, late winter –early spring evening low temperatures which only occasionally fall below freezing, and warm summer and early fall temperatures which are moderated in the afternoon and evening by coastal cooling, often accompanied by fog. A more precise measurement of the vineyard region climate is the climate zone system developed by the viticulture and enology department at the University of California at Davis. This system separates vineyards into regions which are classified by heat summations expressed as degree-days. The degree-days of a particular region are determined by averaging the maximum temperature readings every day between April 1 and October 31, and then subtracting 50 degrees per day (the temperature at which a grapevine begins active growth). Climate maps in Hugh Johnson’s Modern Encyclopedia of Wine and the University of California/Sotheby Book of California Wine both show Spring Mountain at the boundary between Region 2, defined as 2,500 to 3,000 degree-days, and Region 3, defined as 3,000 to 3,500 degree-days. My review of climate data from the region places Spring Mountain in Region 2, a cool grape growing climate similar to that in the Bordeaux region of France. The preceding classifications delineate the climate of Spring Mountain in a general manner. From evaluating weather data gathered in the region and visiting the area, I found clear evidence that Spring Mountain has a distinctive microclimate, with unusual characteristics resulting from the region’s geography and location. A comparison of temperature data from stations within Spring Mountain’s proposed boundaries with equivalent readings in nearby locations shows the distinctive nature of the region’s microclimate. In readings taken between April 1 and October 31, generally considered the growing season for wine grapes, daily maximum temperatures were from two to eleven degrees lower at Spring Mountain than in St. Helena, less than four miles away. Conversely, daily minimum temperatures at Spring Mountain were generally higher than those recorded in St. Helena, often by more than ten degrees. Similar comparisons of Spring Mountain maximum and minimum temperatures with those in Calistoga, less than eight miles away, produce the same results, with even greater temperature differentials between the two locations. Spring Mountain’s lower daily maximum temperatures and higher daily minimum temperatures relative to St. Helena and Calistoga result from the natural temperature inversion found in many coastal valleys. While the cold air settles to the valley floor during the night, and hot air is “captured” on the valley floor during the afternoon, Spring Mountain’s upland location moderates these temperature extremes. Spring Mountain’s primarily eastern exposure also contributes to the region’s distinctive climate. A review of daily thermograph readings taken during the summer and early autumn shows that the temperature on Spring Mountain rises relatively rapidly until reaching a maximum high at approximately 3 p.m., then declines with similar speed during the late afternoons. The daily maximum temperature is reached approximately one hour earlier than in St. Helena, and the temperature peak is very brief when compared to locations on the floor of the Napa Valley. The eastern exposure of the region puts it in full sun during the morning, but only oblique light in the afternoon, and thus plays a major role in the early temperature peak on Spring Mountain. The Spring Mountain region’s location and geography play a special role in its rapid afternoon cooling during the summer and early fall. As with the rest of Napa Valley, Spring Mountain usually experiences advection cooling in the late afternoon, as cool air is drawn from San Francisco Bay by low pressure derived from inland heating. However, Spring Mountain is only 30 miles east of the Pacific Ocean, and the relatively flat Santa Rosa Plain that separates the Pacific Ocean from Spring Mountain enables cool air from the ocean to be drawn over the summit from Santa Rosa Creek and into the region. As a result, the Spring Mountain region often experiences advection cooling directly from the Pacific at times when the pressure differentials between inland locations and San Francisco Bay are insufficient to draw cool air from the bay. The region regularly enjoys cool breezes and occasional fog from the west when the rest of Napa Valley, including hillside locations both north and south, remains hot. Spring Mountain’s advection cooling from the Pacific Ocean is very unusual for an inland eastern slope hillside location, and results from special topographic influences. The proximity of the Pacific Ocean and the flat terrain of the Santa Rosa Plain and Santa Rosa Creek (which reaches 1,000 feet elevation only a mile from the western boundary of Spring Mountain) enable cool air and fog from the coast to flow easily over the summit of the Mayacamas Mountains at this location. Also, the summit above Santa Rosa Creek is just low enough (at 1,900 feet elevation) to provide a gap through which ocean breezes and fog can flow into Napa Valley. On the eastern slopes of the Mayacamas Mountains, advection cooling directly from the Pacific Ocean appears to be unique to Spring Mountain. To the south, summit elevations are higher by several hundred feet, and this, coupled with the greater distance cool ocean air must travel and decreased barometric pressure differentials due to the proximity of San Francisco Bay, keeps advection cooling from the Pacific Ocean from crossing the summit. To the north, advection cooling from the Pacific Ocean is weakened by the greater distance it must travel, and effectively blocked from flowing over the summit by a series of coastal ridges, including the broad base of the Mayacamas Mountains in this area. Spring Mountain experiences greater annual rainfall than the floor of Napa Valley. The Mayacamas Mountains force the moist air masses in winter storms upward as they move inland along a southwest path from the coast, causing precipitation. Isopleth maps of precipitation prepared by the Army Corps of Engineers show an average annual rainfall in the Spring Mountain region of approximately 37 inches, more than the seasonal normal of 33.11 inches in St. Helena. Although Spring Mountain averages more rain than locations on the floor of the Napa Valley, records indicate that other locations on the Mayacamas Mountains between Sonoma and Napa Counties have similar annual rainfall averages. In summary, I conclude that Spring Mountain has distinct microclimate. The region’s location, geography and aspect produce the significant climatic variations previously discussed, and certainly influence the character of the grapes grown in the region. Steve Newman
Weather and the San Francisco Bay Region, By Harold Gilliam, University of California Press, 1966. Meteorology, The Earth and its Weather, By Joseph Weisberg, Houghton Mifflin Co., 1976 California’s Many Climates, By Ernest Felton, Pacific Book Publishers, 1968 Weather – A User’s Guide to the Atmosphere, By Ti Sanders, Icarus Books, 1985
The Spring Mountain region is located on the eastern slope of the Mayacamas Mountains. The region consists entirely of residual upland soils, almost equally divided between those derived from volcanic rock and those derived from sedimentary rock. The residual soils in the region are completely different from the alluvial soils on the floor of the Napa Valley, to the east. Moreover, the upland soils in the proposed viticultural area are substantially different in composition from upland soils in the surrounding areas of the Mayacamas Mountains, due to variations in erosion, dissection and microclimate. The deep, well-drained soils in the region provide vines adequate moisture during most of the growing season, but stress the vines during late summer and early autumn, as the grapes are reaching maturity. Such stressing limits yields, but produces grapes with concentrated varietal character. While classified as Region 2 under the climate system developed by the viticulture and enology department at the University of California at Davis, the proposed Spring Mountain viticultural area has a very distinctive microclimate. The region’s hillside location and valley temperature inversions combine to give Spring Mountain warmer daily minimum temperatures and lower daytime maximum temperatures than locations on the floor of the Napa Valley. The region’s eastern exposure produces earlier daily maximum temperatures, and maximums of shorter duration, than those experienced on the valley floor. The region’s topography and location – only 30 miles east of the Pacific Ocean, with no intervening ridges – often allow afternoon advection cooling (and occasional fog) directly from the Pacific Ocean at times when the pressure differentials between inland locations and San Francisco Bay are insufficient to draw cool air into the Napa Valley from the bay. This advection cooling directly from the Pacific Ocean is unique to Spring Mountain, and does not occur along the Mayacamas Range either south or north of the proposed viticultural area. This climate, with moderate daily maximum temperatures of short duration and rapid afternoon cooling during the growing season, provides an exceptionally long growing season for grapes. The moderate temperatures and rapid afternoon cooling enable the grapes to ripen fully while preserving the natural acidity that is essential for balance in wine. As a result of these geographically created elements, wines produced from grapes grown in the proposed Spring Mountain viticultural area display concentrated varietal character, excellent balance and unusual finesse. This distinctive and uniform regional character has been consistently recognized, and is a clear and tangible argument for creation of a Spring Mountain viticultural area. 4. DESCRIPTION OF SPECIFIC BOUNDARIES OF PROPOSED SPRING MOUNTAIN VITICULTURAL AREA. The following four United States Geological Survey topographical maps are used to show the boundaries of the Spring Mountain viticultural area: 1. “Kenwood, California Quadrangle” 2. “Rutherford, California Quadrangle” 3. “St. Helena, California Quadrangle” 4. “Calistoga, California Quadrangle” The boundaries of the proposed Spring Mountain viticultural area are located in Napa Country, California, and are as follows: Beginning at the point where Sulphur Creek, running through Sulphur Canyon, crosses the 400 foot contour in the northwest corner of Section 2 of Township 7 North, Range 6 West, Mount Diablo Base and Meridian; thence east and then north along the 400 foot contour approximately 9.5 miles to the point where it crosses Ritchie Creek in Section 16 of Township 8 North, Range 6 West, Mount Diablo Base and Meridian; thence west southwest along Ritchie Creek approximately 2.2 miles to the point where it crosses the boundary between Sections 17 and 20 of Township 8 North, Range 6 West, Mount Diablo Base and Meridian; thence due west in a straight line along the section boundary approximately 0.8 mile to the point where it crosses the boundary between Napa and Sonoma Counties between Sections 18 and 19 of Township 8 North, Range 6 West, Mount Diablo Base and Meridian; thence generally south and east along the boundary between Napa and Sonoma Counties approximately 9.3 miles to an unnamed peak, elevation 2600 feet; thence northwest in a straight line approximately 0.10 mile to the source of an unnamed tributary of Sulphur Creek; thence north along the unnamed tributary of Sulphur Creek approximately 1.5 miles to the point of confluence with Sulphur Creek in Sulphur Canyon; thence east along Sulphur Creek approximately 0.5 mile to the 400 foot contour, the point of beginning. # # #
Spring Mountain has been informally recognized as a viticultural area for decades. The purpose of this petition is to gain for Spring Mountain the formal recognition as a viticultural area that the region merits and deserves. We feel that the historic and geographic evidence presented in this petition thoroughly support the establishment of the Spring Mountain viticultural area.
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