Hello Chris,

There is another fault there just north of the aftershock sequence. The Yuha Well fault is between the Laguna Salada and the southern terminus of the Elsinore. Just guessing-----but there could be a blind section of the Yuha fault that extents west toward the Jacumba pluton field. It has not been studied all that much. Something is there....I don't know for sure---conjecture...

http://quake.usgs.gov/recenteqs/FaultMaps/116-33.htm

Glen