As playgrounds of the rich, famous and notable go, quiet Sonoma Valley seems nearly in retirement, full of names ripped from yesteryear's headlines and long since senesced into the landscape. Take Arnold Drive. Who's Arnold? That'd be "Hap" Arnold, the five star general who, along with other WW II brass, was a guest of former art model and famed sugar heiress Alma de Bretteville Spreckels. "Big Alma" greeted guests with a martini in one hand and wasn't keen on the bumpy, dusty road leading to her 3,000-acre Sobre Vista ranch. So she had a seven-mile stretch paved and named for the general.

That's the type of trivia learned during a tour of this 40-acre estate carved out of Spreckel's old ranch in the early 1970s, hidden away off Arnold Drive. Here Robert Hunter, a retired banker with a fondness for the wines of Epernay, has been quietly producing méthode champenoise sparkling. The small staff offer a limited schedule of tasting and tours of gardens designed by 20th-century landscape architect Thomas Church.

Our guide breathlessly related a century of history, and then introduced the unusual flora planted to green up Church's design. An unassuming shrub turns out to be rare, 200-year-old dwarf sequoia, and if the landscaping seems familiar, it's because Church was the father of the now ubiquitous "California" landscaping style.

At the patio tasting, Mr. Hunter himself, at better than 80, is an energetic host, graciously passing the dump bucket, collecting glasses, and engaging us on the finer points of Champagne. The star is the 2000 Brut de Noirs Sonoma Valley sparkling wine ($45). Is that getting on a bit for a white wine? Not so for those with a structure that helps them improve with age; with Champagne, the practice is called extended tirage. Bready, flakey pastry aromas introduce but don't dominate delicate citrus and pear flavor; the lean, clean center of acidity and fine bubbles are refreshing, not scoury. Surprise—fine sparkling wine hails from the warm "banana belt" of Sonoma Valley—and that's not just the phenomenon of "tasting room palate" talking. I found the previous vintage of this bubbly quite by random a few holiday seasons ago, and to my memory it still bests anything since.

The full-bodied and languid 2007 Chardonnay ($35) perked up a little with coconut and Meyer lemon notes. A comparison tasting found the 2005 Pinot Noir ($45) imbued with brown spice and cranberry-grape jelly fruit; limpid but not heavy or hot, it finishes with a brief, satisfying astringency, while the 2003 Pinot Noir ($50) was lithe, silky and aromatic of smoky strawberry jam. Plus, an olallieberry scented, juicy and polished Cabernet Sauvignon ($50) with soft tannin in the background. Cab next to Pinot? Here in Glen Ellen, yes.

Missing was the requisite méthode champenoise demonstration, but for resident tourists or visiting relatives with a taste for the intimate rather than glitz, here is a hidden gem on the wine road less traveled.

Robert Hunter Winery, 15655 Arnold Drive, Sonoma. Tours of private estate by appointment only, $25. 707.996.3056.

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