Trinity Lakes AVA

Trinity Lakes AVA received its official designation on February 27, 2005, from the Alcohol and Tobacco Tax and Trade Bureau. The region takes its name from Trinity Lake and Lewiston Lake, both man-made reservoirs constructed in the late 1950s and fully filled by 1961. Before the lakes existed, the land had served as cattle pasture and hay fields for over a century, and viticulture was not viable until the reservoirs transformed the local microclimate. Mark Groves of Alpen Cellars planted the first vineyard in 1981, pioneering commercial viticulture in the area.

• AVA established February 27, 2005
• Trinity Lake and Lewiston Lake completed by 1961, enabling viticulture
• Area was cattle pasture and hay fields for approximately 100 years prior
• First vineyard planted 1981 by Mark Groves of Alpen Cellars

Trinity Lakes falls within Region I to Region II on the UC Davis heat summation scale, making it one of California's cooler growing environments. The surrounding lakes provide a critical moderating influence, with Trinity Lake cooling warm summer days and retaining heat to warm cool nights. Summers bring sunny days with average highs reaching 93°F (34°C) in July and August, while winters turn cold, with average lows of 27°F (-3°C) in December and January. The rainy season runs from November through May, with average annual rainfall of 44 inches (1,100 mm), leaving a dry growing season that benefits fruit concentration.

• Region I to Region II heat summation classification
• Lake effect from Trinity Lake moderates both daytime and nighttime temperatures
• Average summer high 93°F (34°C); average winter low 27°F (-3°C)
• Average annual rainfall 44 inches (1,100 mm); dry season during growing months

The appellation sits within the Whiskeytown-Shasta-Trinity National Recreation Area, encompassing rugged, mountainous terrain that severely limits agricultural potential. Well-drained alluvial fans occupy narrow valleys on stream terraces, and the best vineyard sites feature rocky, thin soils composed primarily of shale and sandstone. These challenging soils restrict vine vigor and force low yields, concentrating flavors in the resulting fruit. The high elevation, ranging from 1,500 to 4,000 feet, reinforces the cool-climate character and extends the growing season with significant diurnal temperature variation.

• Soils primarily shale and sandstone, thin and rocky with excellent drainage
• Well-drained alluvial fans on stream terraces provide the best vineyard sites
• Elevation 1,500 to 4,000 feet (460 to 1,220 m)
• Stress-inducing soils produce smaller yields of more concentrated grapes

Trinity Lakes focuses on early-maturing vinifera varieties well suited to its cool, high-elevation climate. Riesling, Gewürztraminer, Pinot Gris, Chardonnay, and Pinot Noir are the primary plantings, alongside Blaufrankisch and Merlot. The combination of cool temperatures, rocky soils, and significant diurnal swings produces wines in a delicate, cool-climate style with bright natural acidity and concentrated aromatics. Only two commercial wineries operate within the AVA boundaries: Alpen Cellars and One Maple Estate Vineyards and Winery.

• Key varieties: Riesling, Gewürztraminer, Pinot Gris, Chardonnay, Pinot Noir, Blaufrankisch, Merlot
• Cool-climate style with emphasis on early-maturing varieties
• Rocky, thin soils produce concentrated, lower-yield fruit
• Only two commercial wineries: Alpen Cellars and One Maple Estate Vineyards and Winery