Newark is a city in Alameda County, California, United States. It was incorporated as a city in September 1955. Newark is an enclave, surrounded by the city of Fremont. The three cities of Newark, Fremont, and Union City make up the "Tri-City" area. Its population was 43,539 in 2014. The southern end of the San Francisco Bay lies near the western edge of the city. State Route 84 runs through the city, and continues as the Dumbarton Bridge to cross the San Francisco Bay to reach Menlo Park. Interstate 880 serves as the eastern boundary with Fremont.