This is a two stage cache, a short drive from each other. The first will take you to the stone obelisk marking the Portolà Expedition, and the final will take you to Gaspar de Portolà's "grave."
Final coordinates: How many tiers does the stone obelisk have? (Start with the taller base tier with a rectangle etched in) Make this number A.
N 33 56.(A)(A-2)(A+4) W 117 52.(A+2)(A-3)(A+5)
Don Gaspar de Portolà visited Brea Canyon in 1769. Portolà was on his famous expedition from San Diego to Monterey. He was sent by Spain to claim the land and bring Christianity to the natives.
The expedition passed trough the Brea/Fullerton area on their way north. They established the Sam Gabriel Mission located in present-day San Gabriel. Don Gaspar de Portolà was appointed Govenor of Las Californias, which included Baja California and Alta California, from 1768-1770.
I have created a GeoChecker.