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.