Looking at the Yamhill-Carlton District AVA map, you see it's a horseshoe shape with western, northern, and eastern flanks. Most if not all of this AVA shows the typical rounded hills of sedimentary soils, unlike the steeper volcanic slopes of places like the Dundee Hills, much of the Chehalem Mountains, and Eola-Amity Hills.
The soils are important at least because of what they lend to their wines. I find that the sedimentary soils give a darker fruit character to the Pinot Noir, as opposed to the red fruit that seems to predominate in the wines from volcanic soils. That's conventional wisdom to some, but heresy to others, including many experienced winemakers, who suggest that red and black fruit flavors reflect degrees of ripeness in wine grapes. Less ripe tending to the red, more ripe to the black. The issues isn't settled, that's for sure.
The Yamhill-Carlton District is elevation-based, so that the AVA begins at the 200 foot elevation rising to 1000 feet. The rationale is that the particular soil types in the AVA are distinguished from the fertile valley bottom soils that are not ideal for growing high quality vinifera grapes. Learn more about the AVA here.
From the western flank, which is just north of the McMinnville AVA, we first find a scattering of coast range vineyards. Are these actually volcanic soils? I'll have to find out. Moving north, we find the large Gran Moraine vineyard of Premier Pacific Vineyards, famous (or infamous) for being an investment of pension money from state workers in California. This is an interesting site, due west of the town of Carlton and immediately next to the well regarded Resonance Vineyard.
To the north, we find another wide scattering of planted sites, some with familiar names, others obscure. Lazy River makes its wine (and I believe is a partner in) the Carlton Winemakers Studio. Elk Cove's Mount Richmond Vineyard has long produced a single vineyard bottling. The Estate Vineyard of Elk Cove is further north, along with the long planted but not always highest quality Kramer Vineyard. To the northeast, notice ADEA, with a small vineyard at low elevation right off Route 47. Also, Elvenglade, perhaps one of the more interesting sites for Pinot Gris. Outside the AVA to the north are the well regarded Patton Valley Vineyards and the isolated but beautiful Cancilla Vineyards of Ken Cancilla, an old acquaintance who's making good wine.
Then to the eastern flank of the Yamhill-Carlton AVA. From north to south, the first cluster of sites contains the Beacon Hill Vineyard, a longtime but now former source for Soter, then the patchwork of parcels of Willakenzie Estate, whose name comes from the soil series of ocean sediments this region is known for.
Moving south, there's the Deux Vert Vineyard, notable for some unusual grapes for this area, including syrah. I'm guessing this is a warm microclimate. Then the large Yamhela Vineyard, and to the southeast the very well known Shea Vineyard. You can see that Shea is actually two distinct parcels, which are further broken into numbered blocks that go to specific producers. In Burgundy, Shea might be an entire appellation. Here, it's all one site. But there are some big differences in the blocks. Check out more detail here.
Moving back to the southwest toward the town of Carlton, we find a northwest to southeast ridge with some of the most attractive sites in the whole AVA. Near the town of Yamhill, there's the Blackburn Road corridor, with the long planted Wahle Vineyard, where I got grapes for my homemade wine in 2006. Also, Stag Hollow and at the east end of the road, Ken Wright's estate Savoya Vineyard. This is a nice neighborhood for Yamhill-Carlton Pinot Noir. To the south, there's the beautiful slope of Belle Pente and a few sites of Lemelson, anchored by the Stermer Vineyard.
Finally, due west of the Dundee Hills AVA, there are sites like Mineral Springs -- Soter's new estate vineyard -- Abbott's Claim, Bayliss, Monks Gate, all the way down to the Anne Amie Estate Vineyard almost on the border of the town of Lafayette.
Next, the Eola-Amity Hills.