S12 - Jesmond Dene to Carlsbad, San Diego County, California, USA

Another county route in zone "S" of the California Route Marker Program
beginning in a small community called
Jesmond Dene, named after the park in Newcastle England heading west
San Marcos is the next town the route passes through after passing briefly through part of unincorporated Escondido
Carlsbad is next on this route where it ends near the ocean
The route begins west from Jesmond Dene as
Deer Park Rd & makes a right turn in San Marcos onto
W San Marcos Blvd it transitions into
Palomar Airport Rd as it enters Carlsbad which takes it all the way to its western terminus at S21 (Carlsbad Blvd)