They can be caught from outside the mouth of the CT River all the way up to the Holyoke dam rear-round. One big difference in the CTR as opposed to the other more popular rivers across the state is the CT is more suited to boat fishing in the winter months. You can do ok from shore but you'll do much better by boat.
"Out there in the surf is where it's at, that's where the line gets drawn in the sand between those who talk fishing and those who live it."
- a wise man.