The River Junction AVA, which lies within the larger Central Valley appellation, is a 1300-acre (526-ha) wine region located in southern San Joaquin County at the point where the San Joaquin and Stanislaus rivers converge. The climate here is cooler than in the surrounding areas of the Central Valley. The AVA is also distinctive because of the free-draining, fine and sandy loam soils that are found here.
Due to the versatile terroir a wide selection of grape varieties is able to flourish in the River Junction area, with Chardonnay being the most abundant.