The connection between different wineries from radically different regions often is not evident until you look below the surface.

The parallels between two California wines last week wasn't initially evident, until I saw that the parallels were related to something rather basic: the soils from which they get their fruit.

Both prefer to make wines that show their regional characteristics, and both want to honor those who pioneered their respective regions.

Amapola Creek is a small, prestige winery in Sonoma Valley whose owners, Richard and Alis Arrowood, are making remarkable strides.

Among their top wines is a stellar Cabernet Sauvignon, a terrific Syrah, dramatic Zinfandel, and a superb Chardonnay.

Alta Maria Vineyards is a joint project between grower James Ontiveros and winemaker Paul Wilkins in Santa Maria Valley, in the central coast. The winery makes a brilliant Chardonnay, a sublime Sauvignon Blanc, and a classic Pinot Noir.

Since the wines are rather different in style, you might think nothing connects these two properties. But the connections are soil-based.

Arrowood, who was Chateau St. Jean's first winemaker in 1975 and then went on to found his own eponymous winery, set up Amapola Creek after his own winery was sold.

And visiting his secluded project recently, I asked why he chose this Sonoma Valley hillside property, just down the road from where he has made wine for nearly 40 years.

"I was looking for a special hillside property, and I knew that one of the best vineyards in California was Monte Rosso, so we decided this place was best," said Arrowood.

Monte Rosso, owned for decades by the Louis M. Martini Winery in St. Helena, long has been prized for its Cabernet Sauvignon and old-vine Zinfandel.

After the Martini winery and vineyards were sold to E&J Gallo, Arrowood was one of the few wineries clamoring to get some of its prized fruit.

His long history as a brilliant winemaker not only gave him access to some Zinfandel grapes, but also the right to use the vineyard's name on the label.

And he planted his now-20-acre vineyard literally the other side of a fence from those famed vines.

Arrowood today makes some of Sonoma County's most prized wines from his ranch, as well as the exciting Zinfandel from Monte Rosso. The 2010 Zin ($48) is one of the best in the state.

Sonoma Valley fruit has long driven Arrowood's passions for wine, and it is the main reason he remained just down the road from St. Jean after he left that project.

Moreover, what is reputed to be California's first Cabernet Sauvignon, called Duneden, was grown in the 1870s just north of Amapola Creek in nearby Kenwood.

Alta Maria's Wilkins worked as assistant winemaker at Alban Vineyards in Arroyo Grande before striking out on his own a few years ago with his partner, grower Ontiveros, guiding the vines.

Wilkins could have moved to a more prestigious location, but says, "We have a great deal of respect for the people who came before us here. It's really important to retain a sense of place and personality in these wines."

I was struck by the fact that all of his wines remind me of Santa Barbara's first serious efforts from the early 1980s.

Wilkins seeks to make wines "that resonate with the history of this area. I wouldn't want to be anywhere else."

Three recent releases from Alta Maria, a light and elegant Chardonnay ($28), a stylish and exciting new style of Pinot Noir ($28) and a delicate Sauvignon Blanc ($19) all are priced below the market for their quality.

The Arrowoods and Wilkins of the California wine business are reasons to cherish California as a wine-growing mecca.

Wine of the Week: 2011 Healdsburg Ranches Merlot, California, "Coastal Series" ($13) — This screwcapped light red wine has a fresh fruit and an appealing lightness, a bit like Pinot Noir in structure.

A companion Zinfandel ($13) also is a nice little quaffer.

Dan Berger lives in Sonoma County, where he publishes "Vintage Experiences," a weekly wine newsletter. Write to him at winenut@gmail.com.