I fish the red river that flows north from north dakota into manitoba. No flat heads, but plenty of channels. Biggest I've caught out of it so far is around 15 lbs, but I know there are some that are pushing 30 lbs in here. Just gotta find'em.
Seppi my understanding is that everyone uses live fish for flats? What's your go-to? Might round up some sunfish and head to river with them. And how've you been doing with channels? I haven't caught a single one this year! Just tons of bullheads.
Been using live green sunfish and cut bait ( frozen shad mainly) my friend just caught this one last night on a 4" bluegill head. I've caught channel cats but usually just in tributaries off of the Ohio river. And I've only caught them on chicken liver