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The Terroir of the Petaluma Wind Gap

A few years ago, I was privately doing a lot of reading and writing about Green Valley of the Russian River Valley.

Something that was a bit elusive for me was actually grasping exactly where the Petaluma Wind Gap originates. Everyone writes about it, but knowing exactly where it comes in is not as well pinpointed. At least, that’s what I thought until I finally fell unto the Petaluma Gap Winegrowers Alliance site. Their tag line is From Wind to Wine. I wanted to know as much about it as I could, because it helped me to define terroir for Green Valley; in my own words, though my own understandings.

Terroir is actually best described by someone who is French, to be really honest with you. I’m French, in part, and I just know this from knowing my own family members who raised me. This is because you not only get the adjectives, but you get the body language; the romance, the reason I want to go to France, words like “when the earth vibrates…” You get so much more than what a dictionary can deliver… You get the essence. I was reminded of this when I sat listening to Véronique Raskin, from The Organic Wine Company. She’s a woman so powerful that in her presence, you know the gods sent her down for a very specific purpose, which is another story for another time… But for today, terroir from her lips, and her arms, and her hands, and her facial expressions lets you know, there’s something akin to magic vibrating up from the earth, which delivers wine for very important purposes. And is part of terroir… as you begin to think of everything else you’ve read and heard about what terroir is.

And so, I continued on my terroir journey, by exploring the Petaluma Wine Gap, in order to clearly “get” the Green Valley of Russian River Valley.

The Wind Gap affects not only wines coming from the Petaluma area, but it also winds its way inland, and affects wines coming from Sebastopol and Graton of Green Valley, too. These are the coolest regions in Russian River Valley. Since Petaluma is south of Sebastopol and Graton, I’ve had to follow the stream southward to try to find the exact point of entry. It was confusing for me, because I was expecting a very narrow funnel effect… But, I learned otherwise.

First, from the Petaluma Gap Winegrowers Alliance site:

The wind and the fog are the Petaluma Gap’s trademark. The “Gap” is actually a wind gap named after a coastal mountain opening that stretches east from the Pacific through the town of Petaluma and then roars south to San Pablo Bay.

This is a great definition, but it’s not visual, and I’m a visual learner. I needed to see the exact point of entry… With this explanation, I could see where it goes… but the point of entry still remained a mystery to me. One flaw in that explanation for me, though, was its southerly to northerly flow. What about when the winds are coming in from the south and pushing northward — specifically through Petaluma, headed toward Sebastopol and then up to Green Valley?

Then, it occurred to me, because my daughter and her family were living in Petaluma. From Petaluma, we can easily drive to Tomales Bay. We’ve been there and watched the fog roll in in late afternoon. If you’re on the beach, you can visually see the fog rolling into that valley area, and understand the pinpoint location of the Petaluma Wind Gap on its southern end. I’ve been there when it happens… It just rolls in. It’s cold and windy, and it just takes over. We ran from the beach.

So, Tomales Bay is a logical point of entry, but wait… I feel like one of those sleazy TV ads… We’ve got one more entry point for you! Bodega Bay…

From Wiki about the Petaluma Gap:

The Petaluma Gap is a geographical region in Sonoma County, California, which extends in a band from the Pacific Ocean to San Pablo Bay. It is an area of low land 22 to 31 miles (35 to 50 kilometers) wide in the coast ranges of the northern San Francisco Bay Area. The western edge of the gap is located in the coastal lowlands between Bodega Bay and Tomales Bay. The eastern edge of the gap is located at San Pablo Bay around the mouth of the Petaluma River. The city of Petaluma is near the center of the gap.

And so, back to the Petaluma Gap Winegrowers Alliance:

Geographically, the Petaluma Gap borders West Marin and Valley Ford on the west, then follows Chileno Valley and Spring Hill Roads to Adobe Road on the east, Cotati on the north[,] and Lakeville on the southeast. This is not your normal geography. As inland valley air heats up, it pulls the cool coastal air into a naturally formed 15-mile-wide “gap” in the coastal range mountains. The wind flows off the ocean between Tomales Bay and Bodega Bay, builds up speed as it funnels through the gap, then empties into San Francisco Bay. Wind and fog define the area, giving the term “micro-climate” real meaning.

This lowland area, where it comes in through this 15 mile gap point-of-entry, seeps and creeps through each low lying area. Well, if you think about it, fog is a large mass and will seep into any available lowland, coming in through a defined funnel and the blanket of it quietly and atmospherically just takes over the lowlands. And, this is the chilling air coming into Green Valley that defines its cool climate. This makes this AVA the most perfect place in all of the Russian River Valley for growing the cool weather crops of Pinot Noir and Chardonnay.

Here’s your visual, from a Google map.

8 Responses to “The Terroir of the Petaluma Wind Gap”

  1. Ward Kadel says:

    Fantastic piece Jo, thank you for researching and posting this. I hav often wondered the same thing (as a scientist): where exactly *is* the Petaluma Gap. I now have a much better idea, thanks to your post and the map, as well as my own many years going to Tomales and Bodega Bay. :-). Cheers!

  2. Jo Diaz says:

    Thanks for letting me know, Ward. It took time to dig it up the way that I could understand it. Happy I got to the bottom of it; for not only me, but also for others with the same wondering.

  3. Matthew Levy says:

    Hi Jo,
    Great explanation of the Gap. It is always wonderful to see these micro-climate regions gain some recognition. We are big fans of grapes from the Petaluma Gap, having sourced grapes from vineyards in this area for both our Schramsberg sparkling and Davies Vineyards still wines over the last 15 years or so. Cheers to you!

  4. Damien Wilson says:

    Thanks for the interest, and explanation Jo. As one of the Directors of the Petaluma Gap Winegrowers Alliance board, it’s heartening to read of both the interest and assistance you’re providing your followers as a means to discover our region. The Petaluma Gap’s windswept landscape is already responsable for crafting some of the most sought-after Pinots, Chardonnays and Syrahs in the US. When the day finally arrives where ‘Our Gap’ is recognized as an AVA, we’ll look back with rose-colored glasses on the era when Petaluma Gap wines were affordable. You know the time, before Jo Diaz and contemporaries wrote about our region. Thanks for writing such an illuminating post.

    Yours sincerely,
    Damien Wilson.

  5. Wonderful piece about a misunderstood, often understated … the less acclaimed “Petaluma Gap” wine region. Soon, we hope, it will become the next California, AVA (American Viticultural Area). Excellent description and graphics. Because of the unique terroir this region is most productive. You described and illustrated it well. Pinot Noir, Chardonnay and Syrah thrive here.These wine grapes from the “Gap” are equal to or better than any in the state. That is why many of the most prominent wineries buy from the region and we have the great wineries already here. In the late 19th and early 20th century it was mainly Zinfandel and German varietals. Petaluma itself was home to the largest winery in the state in 1906, and, General M.V. Vallejo had vineyards here as early as the 1840’s.
    A few years ago Paula Freund and myself co-curated an exhibit at the Petaluma Historical Library and Museum called “Petaluma Viticultural History & Heritage: a Celebration of Wine and Community”. We learned a lot.
    Very well received we worked closely with the Petaluma Gap Winegrowers Alliance. Great wine from the “Gap”….Nice blog from you.

  6. Jo Diaz says:

    Mathew, hi. I love vit area aspects. So many subtleties, made over the course of time… One of the greatest joys in my professional life was working with Suisun Valley growers and producers for 10 years. They had government grants, specifically intended for awareness. Our company got the job. My first declaration is that it abuts Napa… Almost too easy, except it didn’t appear that anyone had declare that yet. So, it took some story telling. They’re pretty busy over there right now. I learned and wrote so much about Suisun… still do on occasion. Regionalism… You’re right. There could be a lot more on it.

  7. Jo Diaz says:

    Thank you so much, Jim. It’s an honor to meet you here.

  8. Jo Diaz says:

    Thanks, Damien. The most curious thing for me was a clearly defined visual. Once I had that, it was easy to see how the air would be affecting the vit area. Very sweet compliments. Thank you.

    You’ve got such an AVA catchy name. I only understand how easily it’s going to slip off everyone’s tongue. The Gap! The Gap! High on a windy hill, Pacific breezes of a thick fog blanket… They’ll be writing sonnets and sipping the wines, and we’ll sing, “Remember the days of the no-name gap, that now has a star named after it?” And the other guy will say, “Naw, that was long before my time…”

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