Trefethen Family Vineyards is a historic, estate-driven winery located in the Oak Knoll District of Napa Valley, California, just south of Yountville. The estate centers around a beautifully preserved 19th-century winery building originally constructed in 1886, which remains a defining landmark of the property today. The Trefethen family established the modern winery in 1968, becoming part of Napa Valley’s early wave of pioneers committed to estate-grown wines — a philosophy that still defines the brand.

The vineyards are entirely estate-owned, spanning the Oak Knoll District, a cooler pocket of Napa Valley known for its gravelly loam and alluvial soils that provide excellent drainage and moderate vine vigor. The region benefits from morning fog and cooling bay breezes, which extend the growing season and preserve acidity, making it ideal for a wide range of varieties. Trefethen grows Cabernet Sauvignon, Chardonnay, Merlot, Pinot Noir, and Riesling, among others, with a focus on balance and site expression rather than over-ripeness. The estate is 100% estate-grown and sustainably farmed, reinforcing its commitment to long-term vineyard health and terroir integrity.