I've shown my fascination for oil wells in the Santa Cruz Mountains before, but oil in the Bay Area isn't just under Cupertino and Los Gatos.
This USGS map shows all the oil wells dug in the Santa Clara and San Mateo areas from the 1870's on. Most of the interest has been around the known finds - Moody Gulch in Los Gatos Canyon, the La Honda and Half Moon Bay fields, and the Sargent field. None have been huge producers, but there's still the potential for a big find. If you're looking at a vacation home out in the redwoods, or a 3/2 rancher on 5000 square feet in Cupertino, make sure to get mineral rights!
If I don't give Alma any signs of the Moody Gulch oil production, I'll be very disappointed with myself.