The Finger Lakes area is New York’s largest wine producing region. Over 100 wineries and vineyards are centered around Seneca, Cayuga, Canandaigua, Keuka, Conesus and Hemlock lakes. Because of the lakes’ great depth, they provide a lake effect to the lush vineyards that flank their shores. Retaining residual summer warmth in the winter, and winter’s cold in the spring, the grapes are protected from disastrous spring frost during shoot growth, and early frost before the harvest. The main grape varieties grown are: Chardonnay, Riesling, Gewürztraminer, Pinot Noir, Cabernet Franc, Vidal Blanc, Seyval Blanc and many vitis labrusca (native American) varieties or cultivars. With the passage of the Farm Winery Act in 1976, numerous wineries have opened their doors to visitors from all over the world. Wineries are a major growth industry of the region, not merely contributing to the economy through production, but increasingly because they attract large numbers of visitors who support other components of tourism.