My favorite local river is only about 15' wide. My favorite rod to fish it is my 3 weight TFO Finesse series rod. Second favorite is an 8' five weight. I have tried 7' rods there, and they're too short. For larger rivers I prefer my 9' four weight. Most of our fishing is with nymphs or streamers. A black wooly bugger is killer on most of the rivers I fish here in New Jersey and lower NY State.
