Bolinas-Stinson Union School District was created in 1858.
Saugus Union School District was created in 1908.
Union Hill School District was created in 1868.
Union Local School District was created in 1959.
Washington Union School District was created in 1868.
Reed Union School District was created in 1887.
Rosedale Union School District was created in 1890.
Elwood Union Free School District was created in 1903.
Del Mar Union School District was created in 1906.
Oxnard Union High School District was created in 1905.
Tamalpais Union High School District was created in 1908.
Shasta Union High School District was created in 1899.
Tolleson Union High School District was created in 1914.