American Viticultural Area · CA
Howell Mountain
Howell Mountain is a federally-designated American Viticultural Area in CA, established in 1983. The map below shows its official TTB boundary alongside nearby AVAs.
The Howell Mountain boundary is highlighted. Nearby AVAs are rendered in gray — click any of them to view that AVA's page.
At a glance
Established
1983
State
CA
Climate
Mountain Mediterranean
Signature varietals
Boundary recorded in 27 CFR Part 9 · Source: TTB
About the Howell Mountain AVA
Howell Mountain, designated 1983, was the first sub-AVA approved inside Napa Valley. It sits above the fog line on the eastern Vaca Range — vineyards must be at or above 1,400 feet of elevation. That elevation rule is unusual: the AVA does not include every vineyard on what looks like the mountain on a map, only those above the cutoff, so the boundary follows a contour line rather than a watershed.
Above the fog, Howell Mountain experiences cooler nighttime temperatures and warmer days than the valley floor below, with volcanic and red iron-rich soils that produce structured, tannic Cabernet Sauvignon and Zinfandel. The mountain Cabernets are typically denser and longer-lived than the bench Cabernets from Rutherford or Oakville — a difference that has held up across decades of comparison.
Nearby AVAs
Other American Viticultural Areas closest to Howell Mountain — useful when a vineyard sits inside more than one AVA at once.