The bigger problem is that, during the late 1940's, the oil field (Placerita Oil Field), was known as "Confusion Hill" for all the wells sunk. It isn't likely that all have been found and capped properly either.

Either way... certainly not "the best" real estate by far.

[https://socalregion.com/san\_andreas/](https://socalregion.com/san_andreas/)

[https://socalregion.com/geology/los-angeles-geology/canyon/](https://socalregion.com/geology/los-angeles-geology/canyon/)

Source: Studied the geology of that area for over 25 years and lived there.