Same general area, but about 4 miles SW of the Chino Hills quake.

Although the Chino Fault is to the NE of the epicenter of the Chino Hills quake, the fault dips SW towards the Chino Hills hypocenter. (I do not know if the fault has 'officially' been determined to be the causative fault)

The current quake, being SW of the Chino Hills quake, is closer to the Whittier Fault, which dips to the NE towards the current quake.

These two faults are northern splays of the Elsinore Fault to the SE.

http://www.data.scec.org/significant/chino.html
http://www.data.scec.org/significant/whittier.html
http://www.data.scec.org/significant/elsinore.html

I'd like to point out there was an M4.0 less than a mile ESE of the current quake back on June 14th.

http://www.scsn.org/ (currently the front page quake, but will surely be replaced by the current quake by tomorrow)

Brian