Formed by Delaware River tributaries, the slopes of several valleys contain the best vineyard sites in New Jersey’s Warren Hills viticultural area. The narrow valleys run southwest to northeast, creating numerous southeast-facing slopes which are unique microclimates within Warren Hills. They have warmer than average temperatures and also receive much more direct sunlight and air drainage. These factors, combined with appropriate soil associations, result in prime growing conditions for late-ripening varieties such as Vidal, Seyval Blanc and Cabernet Sauvignon. The appellation, located entirely inside Warren County, New Jersey, covers about 226 square miles, with just over 100 acres currenty under vine.