In the 1880s, the big news on the Coastside was OIL! The Purissima Oil company was drilling for oil near here - and finding it. While none of the wells ever became a big producer, the activity provoked a boom in the now vanished village of Purissima. Repeated exploration in the area over the years produced some minor gushers and some scams.
Minor exploration activity persisted well into the 20th century. As late as the mid-1990s, a rusting well rocker could be spotted on the south end of the ridge visible to east behind Bob's Veggie Stand. Vanished benchmark references testify to the location of other former wellheads.
But a Coastside oil boom isn't likely, even given today's prices. The faulting activity along this section of the California coast breaks potential oil-bearing strata into fragments, rather than concentrating the petroleum into one location. When a reservoir is found, it turns out to be small and quickly tapped out. But if you'd like to try your hand at wildcatting, you can download a California state map (PDF) of past drilling activity in this and other nearby areas. Good luck! (Or maybe you should just hide a cache at one of those historical drill sites.)
The cache is a camo-taped plastic jar in a bush. You do not need to go near the cliff's edge to find it, so please don't!