I think this was native, since nearby feeder creeks do hold native brookies and brookies are not stocked near by
Brookie ... New Jersey's state fish
NJ has tons of native/wild brookies if you know where to target them. And not just in tributaries, but in bigger rivers like the Musky, SBR, Flatbrook, etc.
The fish in the photo is a wild fish and not state stocked.
Native brookies are common in many small creeks in upstae ny...not rare at all