"Look, honey! No dirt!"

The car rings with laughter as Joan and Walt Flowers recall their first glimpse of the Sonoma hilltop that has recently become their latest vineyard. The road into the property is cut into the side of the hill, revealing clearly that there's only a thin layer of soil covering a mass of heavily fractured, reddish colored stone. Today that thin soil and busted rock support 50 acres of vines. "For growing grapes, you couldn't order it up any better than this," says Walt.

Hard to believe someone would order up any kind of vineyard here, where half the view is of the restless blue Pacific Ocean and limitless blue sky. I can gaze 20 miles south along the shoreline, past the mouth of the Russian River and all the way to Bodega Head, near the southern border of Sonoma County. Although we're nearly 1800 feet above sea level, the soft red rock in my hand was once beneath the waves I see crashing down below. As the tectonic plate underlying the Pacific Ocean continues to plow into the North American plate, the ancient ocean floor has been compressed, pushed up, and tilted in all directions. The result is a rumpled series of steep ridges paralleling the water's edge.

When I scan those ridges, I spot more vineyards -- each planted on a knoll or rise along a ridgetop, like solar panels on the roofs of houses. This solar strategy, combined with rocky, well-drained soil, makes the Sonoma Coast one of the hottest new frontiers in northern California wine growing. Without those two factors, this ruggedly handsome but largely impassable area -- with its heavy doses of summer fog, winter rainfall, and year-round wind -- would be too cold and wet to ripen premium wine grapes.

By planting above the fog line, on rocky ridgetops where water drains away from the vineyards, winegrowers have discovered that Chardonnay and Pinot Noir will ripen nearly as well as they do in the much warmer, dryer Russian River appellation to the east. It may take a few weeks longer, and it will likely be more nerve-wracking. In some years, such as 2005, the harvest may also be the kind that makes winemakers weep: less than half a ton per acre, with whole vine rows nearly shorn of fruit by rough weather during the flowering season.

Still and all, there are now more than 50 wine growers in the appellation. “What ties us together out here is extremity," says Daniel Schoenfeld, who established his five-acre Wild Hog Vineyard and winery in a coastal canyon in the early 1980s. The place is so remote he has to generate his own electricity, using solar panels and a small hydroelectric generator in a nearby creek. "The conditions for wine-growing here are extreme," he says, “because of the weather and the wildness of the terrain. People who live here have an extreme love for the land. And the wine itself is extremely intense."

Proof of this last point can be found in any Sonoma Coast bottling from such luminous labels as Kistler, Marcassin, Peter Michael, and Williams & Selyem. Connoisseurs look also for highly-rated Sonoma Coast bottlings from Flowers, Littorai, and Martinelli.

Local residents like to note that the mottled green military helicopters that fly overhead hunting for marijuana plantations now have competition: sleek black choppers bearing millionaires hunting for vineyard sites in an area that’s as beautiful as it is remote.

If only they knew what to call it. The term “Sonoma Coast” officially applies to an area so vast it could swallow up the Napa Valley, Sonoma Valley, and Russian River Valley appellations put together. As defined by the U.S. Alcohol and Tobacco Tax & Trade Bureau (TTB), the Sonoma Coast approved viticultural area (AVA) stretches from the coastline up to 30 miles inland, all the way to the base of Sonoma Mountain east of Santa Rosa. It also runs from the Mendocino County border all the way down to the northern shore of San Francisco Bay.

Along the way, the AVA takes in unimaginably diverse combinations of elevation, soil type, and weather pattern. In twenty minutes you can drive past loamy river bottoms beneath towering stands of redwood trees, through sun-baked hills studded with oak trees, and up into those foggy ridges overlooking the ocean. Fruit farms and orchards, sheep and dairy ranches, and the occasional horse farm are also part of the scenery.

So what does "Sonoma Coast appellation" really mean? Standing on a vineyard ridge near the appropriately named town of Seaview, taking in the scent of the ocean and vistas of breaking waves, the answer seems clear: it's here, where the influence of the Pacific really means something. But industry insiders disagree in surprising ways.

Winemaking superstar Helen Turley once told me that as far as she and her husband, John Wetlaufer, are concerned, "Marcassin Vineyard is our appellation." More than 20 years ago, when they were young unknowns, they tasted a Pinot Noir from the Seaview area. They were impressed enough to scrape together the money for 40 acres of mostly vertical land nearby. Six years later they could afford to have Warren Dutton, one of Sonoma's veteran vineyardists, plant the eight or so acres flat enough to farm. Turley remembers that Dutton called it "the best drained vineyard in Sonoma County." Not surprising, considering that the land plunges away from the vineyard in all directions.

From Marcassin you can see at least half a dozen other vineyards on neighboring coastal hilltops, but Turley believes that geographic proximity isn't enough to justify an appellation. "There's as much difference as similarity," she says, waving her hand to take in the scene. "Just in this little cluster of vineyards, people will start harvest up to three weeks apart for the same grape variety." While such a time-shift is not unknown in other parts of California, it would shock the French, whose definition of an appellation usually includes the fact (if not a legal requirement) that everyone starts picking at the same time.

Coordinating harvest dates was not a top priority when the Sonoma Coast Appellation was created in 1987. Brice Jones, founder of Sonoma-Cutrer Vineyards and the original proponent of the appellation, had a different problem. Like Turley, he believes that vineyards matter most; Sonoma-Cutrer made a splash with its single-vineyard Chardonnays in the 1980s, and continues to produce a series of them today. But Jones (who sold to Brown-Forman in the 1990s) also wanted to put the prestige phrase "Estate Bottled" on his labels. "At that time, to use the estate label your vineyards and your winery had to be in the same appellation," Jones explains, "and my three vineyards were in different parts of Sonoma. The only way to get them all in the same appellation was to create one."

So he did, packaging the entire coast of Sonoma County with a major portion of the interior surrounding his winery in Windsor. The fact that there were few vineyards in this "wine region" didn't stop Jones and his fellow petitioners. Even today, the Sonoma County Grape Growers Association estimates that the Sonoma Coast AVA has only about 7,000 acres of vines, making up less than 1.4% of its total area of 517,000 acres. For comparison, the Napa Valley's 300,000 acres of land include more than 43,000 acres of vineyards, or upwards of 14% of the area.

Today Jones has a different defining rationale for the appellation. "It's basically the half of Sonoma that is cooled by the ocean, as distinct from the eastern half of Sonoma which can get pretty warm," he says. "Everyone agrees today that the best Pinot Noir and Chardonnay come from cool climates such as Carneros and Anderson Valley, and that's what you've got in the Sonoma Coast."

Nonetheless, growers out near the real coast keep talking about a new sub-appellation that recognizes how far they are from Windsor -- physically and spiritually. They feel their true forebears are the intrepid Russian fur traders who arrived on the coast in 1812 and built Fort Ross (condensed from "Rossiya," or Russia). Five years into their stay, they planted the coast's first vineyard. The Russians were eventually forced home by political and economic factors, and it was almost 150 years before the next coastal vineyards were planted by local ranchers Nick Bohan and George Charles.

The pace is clearly picking up. Large corporate wineries such as Kendall-Jackson and Artesa have acquired large tracts near the northern town of Annapolis, an inland area with more moderate elevations (600 to 800 feet) but more extreme swings of temperature. Meanwhile, further south, independent vintners such as Marimar Torres of Marimar Torres Estate and young lions such as Ehren Jordan have planted new vineyards of their own.

The focus so far remains strongly on Pinot Noir and Chardonnay, with Syrah coming up fast (as it is everywhere). It's also possible to find Petite Sirah, Nebbiolo, and even the Bordeaux varieties (Cabernet Sauvignon, Merlot, et al), but these are generally hold-overs from the 1980s or small-scale experiments.

Sonoma Coast Pinot Noir, in particular, seems perfectly timed. It's highly distinctive at a time when American palates are growing more sophisticated about red wines, and intensely flavorful at a time when Burgundian models of chaste restraint have lost their influence.

"I think the great American Pinot Noir is going to come from the Sonoma Coast," says the man who created the appellation, Brice Jones. "Rocky soil, steep slopes, warm sun, and the cool ocean: that's a powerful combination, and we don't have it anywhere like we have it on the Sonoma Coast." The folks down south in the Santa Rita Hills might argue this point -- but that’s another story.