Matt,
Oopps. Yeah, you're right - there wouldn't have been browns until the late 1800s, decades after the dam was built. As for NJ, they started a sea run brown trout program about a 12 years ago in the Manasquan River, which is a fairly short, tidal river in center state that flows directly into the Atlantic. The program has been succesful although hasn't amounted to what some had hoped. Some decent fish, usually over 20 inches and heavy, come out of the river every year. Up in New England, sea run brown trout populations are still fairly common. I'll be FFing coastal Maine next week and there is a river where I fish stripers and in which they get brown trout every year. Although I've yet to get a brown from the beach, I think that would be really cool. There are some sea run brookies up there too but apparently not in the river/beaches I like to fish. I've always wondered how far south viable populations of sea run trout, both brown and brook, existed in the modern era (roughly post 1700). I don't know of any sea run brown trout populations today south of the Manasquan River.