recommendations for extended class II within 6-8 hour drive of BostonMA
 

I'm looking for river recommendations.
I'm interested in rivers that have lots of class II rapids, some
class III is ok. I have done these rivers:

Saint Croix river, Maine
East Branch Penobscott, Maine
Ecores River, near Laurentian Mountains Quebec

Those where all 2 day trips and where pretty good, They also happened
to be rivers that
are canoeable in the summer.

I am interested in rivers that flow through wilderness for say
30 to 50 miles for 2-3 day trips.

I also did the Noir River in western Quebec once, but that was a 6 day
day trip.