O'Shaughnessy produces Cabernet Sauvignon and Chardonnay from Napa Valley's most prestigious mountain terroirs. The winery's Mount Veeder Cabernet Sauvignon and Howell Mountain Cabernet Sauvignon reflect the structure and depth that these high-elevation sites impart—cool nights, volcanic soils, and extended ripening windows that build complexity into the glass. A Chardonnay rounds the portfolio. The wines have been assessed by Wine Advocate, Wine Enthusiast, Decanter, Wine Spectator, and Falstaff.