NE Mason,
Nice set-up!
According to Dr. Dave Willis, for every hour you spend fishing for a rainbow you might spend 20 times that amount of time catching a brown. I believe it; we stocked 240 browns (with 400 rainbows) in our trout pond a year ago and have not seen hide-nor-hair of them (browns) since! It concerns me in the future as we add more rainbows (5-7 inch), will we be feeding larger un-catchable browns.
So to answer your question����.I believe the browns are still there.
Good Luck.
Ed