Cook Forest is a wonderful park with tons of trails and canoeing down the Clarion River.  Campground is vast and hard to pick a spot, though I found the park office helpful in giving me their opinion.  Can be very crowded in the summer and on weekends.  My site ended up not being very private but I had woods along the back which made it better.  Lots of other families around so my son liked playing with the other kids while I made dinner.