Otters were reintroduced into pats of PA a few years ago. Our hunting cabin in PA has a creek behind it that we stock with trout. The otters found our creek and the trout. I don't think those were reintroduced otters though. They were otters from the Chesapeake Bay area where they never were extirpated naturally spreading north and west up the Potomac River watershed as our cabin is right on the PA/MD line. I was amazed at how effective the otters were at catching the trout which were lethargic from border line warm summertime water temps.