OFFICIAL DATA BACKBONE • TTB AMERICAN VITICULTURAL AREAS (27 CFR PART 9)

The AVA Genome

Deconstructing 280 official U.S. AVAs into measurable physical layers: TTB legal boundaries, USGS 3DEP elevation models, NRCS SSURGO soil series, and NOAA climate normals.

TTB STATUTORY APPELLATION GENOME • 27 CFR § 9.23

Napa Valley AVA

Established: January 28, 1981 (Second AVA established in U.S.) • California

Planted Acreage:47,000 ac

Bonded Wineries:~475

TTB Distinguishing Environmental Claim

Recognized Napa Valley's distinct geological graben between the Mayacamas and Vaca mountains with maritime fog intrusion from San Pablo Bay.

I. USGS Topography & Elevation

• Elevation: 0m – 1300m

• Mean Slope: 14°

• Aspect: South / Southwest

Fault-bounded structural graben valley flanked by volcanic Mayacamas and Vaca ranges.

II. NRCS SSURGO Soil Series

Bale Clay LoamGravelly alluvial clay loam (Moderately Well Drained)

Aiken Volcanic LoamCobbley red weathered volcanic clay loam (Well Drained)

Forward Gravelly LoamRhyolitic tuffaceous weathered rock (Excessively Drained)

III. USGS Bedrock Geology

Great Valley Sequence & Sonoma VolcanicsEra: Cretaceous to Pliocene (140 Ma – 3 Ma)

Complex mosaic of marine sedimentary sandstones and shales overlaid by explosive Sonoma rhyolitic ash-flow tuffs and andesite lavas.

Nested Sub-Appellations (16 Sub-AVAs):

OakvilleRutherfordStags Leap DistrictHowell MountainMount VeederAtlas PeakCalistogaCoombsvilleDiamond Mountain DistrictSpring Mountain DistrictYountvilleSt. HelenaOak Knoll DistrictChiles ValleyCarneros (Shared with Sonoma)Wild Horse Valley (Shared with Solano)