The northernmost section of the Napa Valley AVA, Howell Mountain is literally the top of a mountain due east of St. Helena. (The AVA starts at 1400 feet, where the fog breaks, and goes on up to the top.

Like most mountain AVAs, Howell Mountain is sunny and cool, with a level climate. The vast majority of the mountain is planted to Cabernet Sauvignon, with a smattering of Zinfandel and a few other varieties thrown in.

Recently many of the wineries of this region descended (get it?) on San Francisco to show off their recent releases — along with a few archive bottlings. Thoughts follow on everything we tried.

Tasting Report: Wines of Howell Mountain 2012

2008 Aloft Cabernet Sauvignon Howell Mountain Single Vineyard Cold Springs $150 / A / nice blueberry notes, great balance and finish

2007 Arkenstone Cabernet Sauvignon Howell Mountain Obsidian $120 / B / tight, mint notes

2008 Arkenstone Cabernet Sauvignon Howell Mountain Obsidian $120 / B+ / very similar, a bit more rounded

2007 Blue Hall Vineyard Cabernet Sauvignon Howell Mountain Camiana $59 / A- / black cherry, very tart, dessert like chocolate character

2007 Bravante Cabernet Sauvignon Howell Mountain Estate $65 / A- / good fruit here

2005 Bremer Family Winery Cabernet Sauvignon Howell Mountain Estate $85 / B+ / some herbs, tomacco

2005 Bremer Family Winery Cabernet Sauvignon Howell Mountain Estate Cimarossa Vineyard $85 / B+ / similar, touch more tart

2008 CADE Cabernet Sauvignon Howell Mountain $75 / B+ / herbal, mint, slightly chewy, good balance

2008 Cakebread Cabernet Sauvignon Howell Mountain Dancing Bear $106 / A / wonderful balance, cocoa, deep currant notes

2007 Charles Krug Cabernet Sauvignon Howell Mountain Rocky Ridge Vineyard Limited Release $125 / B+ / slightly tight, dried herbs

2008 Cimarossa Cabernet Sauvignon Howell Mountain Rive di Cimarossa $60 / C+ / prune character, raisiny

2009 Cornerstone Cabernet Sauvignon Howell Mountain $80 / A- / 5% merlot added; softens this wine, easygoing

2008 Cornerstone Cabernet Sauvignon Howell Mountain $75 / B+ / harder, more herbs

1994 Cornerstone Cabernet Sauvignon Howell Mountain $350 / B+ / still hanging in but showing age

2005 Dunn Cabernet Sauvignon Howell Mountain $88 / B / Bordeaux style, very earthy

1998 Dunn Cabernet Sauvignon Howell Mountain $110 / C+ / faded, balance is off

2007 Highlands Winery Cabernet Sauvignon Howell Mountain Reserve $70 / B / earthy, bit jammy

2008 Howell at the Moon Cabernet Sauvignon Howell Mountain $75 / A- / a bit closed, lots of character and promise

2007 Howell at the Moon Cabernet Sauvignon Howell Mountain $75 / A / great structure, love the fruit, olive notes

2009 La Jota Cabernet Sauvignon Howell Mountain $65 / B+ / massive, intense, needs years

2009 La Jota Merlot Howell Mountain $NA / C+ / very jammy, overcooked

2009 La Jota Cabernet Franc Howell Mountain $NA / B / typical of Cab Franc

2008 Lamborn Cabernet Sauvignon Howell Mountain $100 / B+ / tight wine, good core, textured

2009 Lamborn Zinfandel Howell Mountain $45 / A- / a refined Zin

2005 Neal Family Vineyards Cabernet Sauvignon Howell Mountain Estate $75 / A- / classic cab structure

2006 Neal Family Vineyards Cabernet Sauvignon Howell Mountain Estate $75 / B / showing young, barnyard characters

2008 Notre Vin Cabernet Sauvignon Howell Mountain $150 / A- / still very tight, highly structured core

2008 O’Shaugnessy Cabernet Sauvignon Howell Mountain $75 / A / perfect, heavy fruit, chocolate undertones

2009 Outpost Cabernet Sauvignon Howell Mountain $65 / B+ / intense, jammy

2008 Pina Napa Valley Cabernet Sauvignon Howell Mountain Buckeye Vineyard $85 / A- / lighter body, not as structured

2008 Pina Napa Valley Cabernet Sauvignon Howell Mountain Buckeye Vineyard $85 / A / raisin touches, bigger body, nice balance

2007 Red Cap Cabernet Sauvignon Howell Mountain $65 / B- / almost port-like, overdone

2008 Red Cap Cabernet Sauvignon Howell Mountain $65 / B / bit more pulled together

2007 Retro Cellars Petite Sirah Old Vine Howell Mountain $36 / C+ / menthol big

2009 Robert Craig Cabernet Sauvignon Howell Mountain $80 / A- / tight now

2009 Robert Craig Zinfandel Howell Mountain $50 / B+ / surprisingly dark, intense

2007 Roberts + Rogers Cabernet Sauvignon Howell Mountain $60 / B+ / jammy, Zin-like

2007 Rutherford Grove Cabernet Sauvignon Howell Mountain Pestoni Family $65 / B / huge menthol character, distracting

2007 SPENCE Cabernet Sauvignon Howell Mountain $65 / A- / touches of herbs, cherries

2007 Summit Lake Cabernet Sauvignon Howell Mountain “Emily Kestrel” $45 / A- / easy drinking

2009 White Cottage Ranch Cabernet Sauvignon Howell Mountain Risa $45 / C+ / very tart, thin