The appellation covers 9,060 acres (14 sq mi) along the flat narrow land towards the northern end of the valley between the Vaca and Mayacamas Mountains.[4] Its soil is mostly loam with good water retention and varying amounts of gravel.[5]
Climate
The area has a Warm-summer Mediterranean climate,[6] and is somewhat hotter than nearby wine growing regions with summer temperatures that often reach the mid 90s Fahrenheit.[7] It receives approximately 40 inches of rainfall per year.
History
In 1860, George Belden Crane planted Mission vines in St. Helena, and the vineyard produced its first wine in 1862. By 1874, the vineyard had produced 500,000 gallons of wine annually.[6]Charles Krug, one of the pioneers of Napa Valley winemaking, founded his winery in 1861 in the St. Helena district.[4] Krug also established the St. Helena Viticultural Club in 1876.[8]
^"§ 9.149 St. Helena"(Title 27: Alcohol, Tobacco and Firearms; Part 9— American Viticultural Areas; Subpart C— Approved American Viticultural Areas). Code of Federal Regulations (e-CFR). Retrieved October 31, 2007.