Paralleling the Alexander Valley to the east, with Lake Sonoma at its head and the Russian River at its foot, the Dry Creek Valley is known for Sauvignon Blancs, Zinfandels, and Merlots of intense fruit character.
Dry Creek Valley is located at the northern end of Sonoma County. Although parallel to Alexander Valley and while sharing some of its characteristics, Dry Creek Valley is separated by a hilly area known as uplands. These uplands are composed of a geologically unique, gravelly material known as Dry Creek Conglomerate which is found nowhere else in Sonoma County.
The Dry Creek Valley lies between the eastern slope of the coastal mountains and the hills above the Russian River watershed. It is sixteen miles long and two miles wide and situated between the Warm Springs/Dry Creek confluence to the north and the Dry Creek/Russian River confluence to the south. With approximately 32 square miles of valley, roughly 20,500 acres are available for agriculture. Historically, grapes have been grown in the area since the mid-1800s.
Well-drained alluvial soils are found in the valleys, alluvial terraces and thinners soils on the hillsides. Volcanic materials are part of the soil make-up in Dry Creek Valley and sandstones and shales create the balance. Gravelly and sandy loam, known as the Yolo type, is found between 20-30 feet deep. This is important because the soil allows deep root penetrations, provides excellent drainage and encourages high grape yields.
Deep root penetration also protects the vine from drought and feeds it a wide variety minerals. These are excellent soils for growing quality grapes. On the hillsides, the soils are less deep and have a higher clay content. Although grape yield is somewhat lower on the hillsides, the grape quality is equally superb. Red soil, Boomer type, is found on the hillsides indicating a higher mineral content.
The climate of the Dry Creek Valley has been established as a Region II by the University of California, Davis. The valley is characterized by a range of accumulated degree days found to be somewhere between 2,800 and 3,500 days. The climate of the area also takes into account the prevailing marine fog intrusion due to the nearby Sonoma County coastline. This influences measurable amounts of photosynthesis, seasonal time of harvest, and sugar accumulation. It is also believed to have an impact on the retained levels of total acid at harvest. What this means is that during the growing season, evening or morning fog cools the vineyards so that the acid and sugar content in the grapes are at optimum levels for making quality wines.
The average rainfall is about 40 inches. Frost season begins in November and continues through March. The actual growing season is 230-260 days, beginning around the end of March and ending in October.