On the old road to Hartland via Woodstock, before you get to Hartland there is (or at least was) a general store on the left with a road next to it. Go down that road, and at some point (maybe a mile or two, can't remember, it was twenty some years ago) there's a brook running under the road, and another road to the left along that brook. Fish that brook for trout. Used to be good when I used to fish there.
A few miles up river from Hartland is the best trout fishing. If you are looking for brook trout, just about any smaller brook running into any of the streams that dump into the SJR are good, not the greatest brook trout fishing on the main streams. Right now at the mouth of Stickney Brook, which is a few miles up river from hartland is great for Rainbows, landed a 4 pound one the other night in the main river, great bass spot too. Very accessible fishing spots and you will be fishing all alone. When you see the old mill saw dust burner along the river that is the spot. Have good luck fishing the brook right behind the burner.
I caught three trout in Stickney Brook last Sunday, two were about 10 inches or so. I did not see any four pound ones though. I stayed on the brook though because I thought fishin in the river is closed from the Dam in perth south to the covered bridge on the St. John.