There is an unofficial "trail" all the way from the Oregon border to the Mexican border. There is an organization called "coastwalk" that sponsors walks on sections and fund raises to gain coastal access. Some of the "trail" is on road shoulders. There are two books out (very detailed guides). I am not sure they are still in print, but I have seen them in many stores. Lorentzen & Nichols: Hiking the California Coastal Trail. Two volumes - 1= Oregon to Monterey 2= Monteray to Mexico. If you want remote coastal hiking the best is the "Lost Coast" of northern CA - this hike is in volume 1 of the two-book series. Coastwalk also has a website.