I don't know if it's literally true on a map, but in my mind Oceanside is the furthest north city in San Diego North County.  Once you get to San Clemente you're in a whole new world!

As I say, I don't know where the line is on the map -- these are just my perceptions.

To me, Camp Pendleton is the divider. Starting from the north of North County it would be Oceanside, Vista, Carlsbad, Fallbrook, San Marcos, Escondido, Solana Beach, Encinitas, Del Mar, Leucadia, Cardiff. Poway and RB are marginal.

South OC is San Clemente,Laguna Beach, those cities up to Irvine, Tustin, and Lake Forest. How's that?

Believe it or not, Camp Pendleton even though a Federal Reservation is in SD County all the way up to San Onofre (and a wee bit further north). The OC (County Line) begin just a bit south of San Clemente. That's a fact Jack! Man, if SD County could only get their hands on that (Camp Pendleton Federal Land, for a tax base an realty development, they would go extatic with joy. San Clemente is the first whistle stop in OC. However, if you jump off the freeway (I-5) either left/right or north/south, you are on Camp Pendleton from waters edge all the way east to fallbrook and beyond and subject to search and seizure, etc...etc...etc.

San Clemente, Capistrano Beach, Dana Point, Monarch Beach, San Juan Capistrano, Laguna Niguel & Laguna Beach all are South Orange County.  Areas like Cota de Caza, Laguna Hills, Aliso Viejo, Newport Coast, Crystal Cove, and Lake Forest all fall north of this zone.

The URL to this simple map may help you orient yourself.

All the other response I read were correct in terms of dividing San Diego v. Orange County.

-- Modified on 4/27/2006 6:44:04 AM