Area code 909 was split from area code 714 on November 14, 1992. By August 1993, dialing of the area code became mandatory. Western Riverside County was split off from 909 into area code 951 on July 17, 2004. 909 still covers small portions of Corona, Riverside, Moreno Valley, and the entire city of Calimesa which are in Riverside County.
Area code 559 is a California telephone area code that was split from area code 209 on November 14, 1998. It covers the central San Joaquin Valley in central California , serving the counties of Fresno , Madera , Kings , and Tulare —an area largely coextensive with the Fresno and Visalia - Porterville metropolitan areas.