Area Code 858 History:
Area code 858 was put into service. Area code 858 was created from a split of area code 619.
Counties in California within area code 858 include:
San Diego County.
Major cities or places in California within area code 858 include:
Area code 858 serves the northern suburbs of San Diego and areas in the northern parts of the city of San Diego, including the larger cities and communities of Del Mar, La Jolla, Pacific Beach, Poway, Rancho Bernardo, and Solana Beach in addition to many smaller communities within the area code 858 service area.