As diverse as the wine grape varieties planted, so are the conditions in which they are grown. Amador's vineyards range from an elevation of 250 feet in the western foothills to 2900 feet in the east. Summer daytime temperatures range from the eighties to more than one hundred degrees, while nighttime temperatures dip into the fifties and sixties due to breezes from the Sacramento Delta and the Sierra Nevada mountains. Such a diurnal temperature shift is good for the grapes because the sunshine produces high acids and high sugar content while the temperature drop stabilizes the acid balance in the fruit.

Another factor that differentiates the grapes in Amador County is the jumble of the soils, from alluvial to decomposed granites, fertile to not-so-fertile, level to steep, and fine to coarse-textured. Amador County's diverse growing conditions have been acknowledged by the designation of one appellation of origin - Amador County, and two American Viticultural Areas (AVA's) - the Shenandoah Valley of California AVA and the Fiddletown AVA.