Free: Contests & Raffles.
Consider going over there well before the season starts and just see if you can talk with some of the employees. They are generally happy to share info. If you wait unit opening morning to speak with them, well... you likely won't get as much info.
You will need to go to the guard gate and get information to enter the watershed
I have the same tag but have not been there for years. I believe the guardshack is still off of the Headworks road past Kanasket Palmer State Park.