Mariposa County is the most southern of the AVAs covered by the Sierra Foothills appellation in California. This county is slightly cooler than much of the rest of the region, and Zinfandel is the most widely planted grape variety, producing hefty, fruit-driven red wines.
The county is at the base of the Sierra Nevada mountains, and most of the area is defined by rocky, mountainous topography. Tuolumne County runs along the northern border with Madera County in the south. Mariposa County is indirectly named for the butterflies that can be seen throughout the region in spring (mariposa being the Spanish word for 'butterfly').
Mariposa County is home to much of the Yosemite National Park, and it is here that the Sierra Nevada ranges rise from rocky mountaintops to snow-covered peaks. As a result, the cool alpine influences that characterise much of the Sierra Foothills are much more pronounced here. While days are warm and sunny, night-time winds from the mountains contribute to the diurnal temperature variation, giving grapes a longer ripening period. This leads to the development of rich fruit flavors in the grapes without sacrificing acidity. Many vineyards in the AVA are planted at altitudes of up to 3000ft (900m) above sea level on rocky slopes.
Mariposa County, like much of the Sierra Foothills region, has a rich history as part of the California Gold Rush of the 1850s. A wine industry quickly sprang up in this time around the European gold miners, who needed an alternative to the wines they enjoyed at home, and the region flourished until the end of the 19th Century. The dwindling population saw most of the vineyards in the area forgotten about until the 1970s and 1980s.
Today, Mariposa County is home to only a few wineries that produce small amounts of boutique wine. The Mariposa County AVA is rarely used on wine labels; most producers opt to use the more widely recognized Sierra Foothills name instead.
