The Napa Valley is 60 miles north of San Francisco, 27 miles long and in some parts less than a mile wide. It is considered among California's finest wine appellations, particularly for Cabernet Sauvignon, prompting some to dub it "the Paulliac of California". Napa Valley is far more compact than its neighbor Sonoma, bordered to the south by the shoreline of the San Francisco Bay; to the north, east and west by the redwood-covered Mayacamas Mountains. It is said that the Napa Valley has more different types of soil than all of France, and its microclimates are so varied that it is possible to gain 20F degrees of temperature in the brief trip up valley from Carneros to Calistoga. Napa is blessed with singular geologic and climatic diversity, resulting in extraordinary vineyards. The gift of nature, partnered with state-of-the-art technology and winemaking skill, has consistently propelled Napa Valley wines to the head of the world wine class.

Given its relatively small size, Napa Valley has a surprising number of sub-appellations. Listed alongside are the varieties particularly noted, but by no means exclusively found, in these districts.

Atlas Peak (Sangiovese) Chiles Valley (Zinfandel, Cabernet Sauvignon, Merlot) Howell Mountain (Zinfandel, Cabernet Sauvignon) Carneros (Chardonnay, Pinot Noir, Merlot, sparkling wine) Mount Veeder (Cabernet Sauvignon, Merlot) Oakville (Cabernet Sauvignon) Rutherford (Cabernet Sauvignon) Calistoga (Cabernet Sauvignon, Merlot) Saint Helena (Chardonnay, Sauvignon Blanc, Cabernet Sauvignon, Merlot) Spring Mountain District (Zinfandel) Stags Leap District (Cabernet Sauvignon) Wild Horse Valley (Cabernet Sauvignon, Chardonnay) Yountville (Cabernet Sauvignon, Chardonnay, Merlot, Sauvignon Blanc)

Also smaller plantings of Semillon, Cabernet Franc, Petit Verdot, Malbec, Syrah, Riesling.

Napa Valley recognized the importance of protecting its existing and potential vineyard sites early on. Strict agricultural preserve laws are in place to prevent runaway development and protect valuable vineyard land. The valley floor in this delimited agricultural preserve is literally covered with vines, with some plantings, though not as many as may be expected, in the benchlands. The mountain vineyards are located on Mt. Veeder, Howell Mountain, Spring Mountain, in Wild Horse Valley and on Diamond Mountain in Calistoga. Interest in developing further hillside sites is keen, but environmental concerns have sparked a debate. The stakes are high: a prime acre of developed vineyard in the Napa Valley is selling for $100,000.