Before 1982, San Diego shared 714 with most of Southern California. The 1982 split assigned 619 to San Diego County and the Imperial Valley. As San Diego grew through the 1990s, the 1997 split created 760 for the eastern desert and Imperial Valley, and the 1999 split created 858 for north San Diego County (La Jolla, Carlsbad, Del Mar) — leaving 619 with central and southern San Diego. Unlike most California metros, 619 has not been overlaid — making it one of the few preserved single-code city centers. A 619 number remains tightly identified with downtown San Diego, the naval base, and the city's border-region business community.