The AVA is defined by steep mountain ridges, which rise directly from the valley floor at 1,700 feet above sea level to heights in excess of 3,000 feet. Approximately nine-miles long and three-miles wide, High Valley is in a rare east-west transverse in the Californian Coastal Range.
High Valley's mountain ridges first formed along a small east-west fault line. During Lake County's volcanic period, Round Mountain rose as an active volcanic cone at the gorge's eastern end. Over time, Round Mountain's lava flows built up the eastern side of the canyon. This sealed off a preexisting creek and formed a lake west of the volcano. The lake eventually crested at Schindler's Creek and drained into Clear Lake. These events created the two distinct growing areas in the AVA: the rocky mountain ridges which are home to our vineyards, and the valley floor.
In addition to engineering this craggy mountain rim, Round Mountain's activity produced different soil types in High Valley than in surrounding grape growing areas. The distinct watershed boundaries mean that soils found with in the High Valley area are derived only from parent material found within the basin. For our vineyards, these include brick-red volcanic cinders and pumice-like gravel and stones. Like many great wine growing areas, these soils provide superior drainage. Chemical analyses of the soils also reveal excellent characteristics for wine grape growing, with higher calcium and potassium, lower phosphorous and magnesium levels than other Lake County and North Coast AVAs.
Additionally, our elevation along with the cooling effects of Clear Lake create a natural and perpetual “wind machine.” Early in the day, the land heats more quickly than the lake waters and cool winds sweep up and over the ridge tops. In the evening, a reverse phenomenon sends dense, cold air down the mountain slopes. During July and August, some of our hottest months, we experience daily temperature swings of 50 - 60 degrees. This intense cooling effect produces better acidities, improved tannin structure, darker color, and more concentrated fruit character.
The volcanic soils, steep ridges and constant cooling winds distinguish our vineyards and give rise to comparisons with other notable growing areas around the world.
