For the trout fishing at Bethany, I haven't ever seen a trout caught out of the lake besides at prim time (right after they stocked it). I'm not saying they aren't in there, just that I haven't seen them.
Carp on the other hand have a pretty good population in there and they are fun. there is bass and pan fish as well in there.
A few years ago my daughter caught a trout in Bethany in the fall while we were carp fishing. It was fat and healthy looking and we carefully released it. I was really surprised since I assumed the water temp would have been too warm in the summer for the fish to survive.
I fished Bethany pond last Saturday. I was using a whole nightcrawler hooked though the head. I was casting around the lillypads hoping for a bass. I had something pick the worm up and run with it twice but I coulnt get a hook set. Got a feeling it was a bluegill. I did see a few fish jump. One was at least 24" long. I had a feeling it was a carp.