American Canyon (previously known as Napa Junction) is a city located in southern Napa County, California, 35 miles (56 km) northeast of San Francisco. It is part of the San Francisco Bay Area. The 94503 zip code is located in the American Canyon community of California in Napa county. You can learn more about Real Estate in American Canyon CA 94503 below, including current Homes For Sale: Condos, Townhouses, Foreclosures and Bank Owned Properties, Short Sales and more. Our Local American Canyon CA Realtors can assist you with selling your home in California or buying your next piece of Real Estate in or around the American Canyon CA 94503 community. Be sure to check out our FREE Instant Home Value wizard to get a quick report on your homes current estimated value.