I believe the trout in that system are sea runners, common to the rivers on both the east and west coast so I would assume they have naturally (unnaturally) spread from there.
Iluvswtas, I am allergic to abalone

but thanks for the offer. I have seen drummer caught off the SCT rocks (on Youtube) but I would rather pursue flathead or small trout. I have reliable reports of trout around the 2lb mark from New R, not huge but big enough. There would have to be bream in there as well given their prolific numbers in other east and west coast rivers.