Located in the Clear Lake Appellation of the Lake County AVA, Two Brothers Vineyard is the result of a primitive geological event. When the ancient volcano Mt. Konocti erupted it formed steep mountain slopes in the surrounding area, with well draining volcanic soils. Two Brothers Vineyard, constructed along a mountain slope, benefits from this ancient geological event.

Many winemakers have observed similarities between its terroir and that of the La Mancha wine region of Central Spain, and Campania, the Italian wine region east of Naples.