U.S. District Court, Northern District of California | 1,557 followers on LinkedIn. The United States District Court for the Northern District of California is one of four federal district courts in California. The Northern District, which was established in 1850, encompasses fifteen counties: Alameda, Contra Costa, Del Norte, Humboldt, Lake, Marin, Mendocino, Monterey, Napa, San Benito, San Francisco, San Mateo, Santa Clara, Santa Cruz, and Sonoma. The court has four courthouses (in San Francisco, Oakland, San Jose and Eureka), fourteen district judgeships (also known as Article III judgeships) and twelve magistrate judgeships.