if you're going to adairs, yes, you are allowed to fish - provincial license required (you don't need a salmon license/tags, no salmon fishin' allowed there.) the streams should probabley be your best target, but the main lake has speckies and char, although the char and be elusive. there are some rainbows in the river and a couple of the lakes. the irving backwoods roads and trails book gives a good overview of the system.
I do believe he will charge you extra to fish for char in the lake next door as he leases that lake, so it's private.
Check the map book for sure for some good places to try. Those old dams hold fish in the spring, but I've never fished 'em this time of year. I never bothered fishing the brooks in that area but I hit all the little lakes now and then. Some are good and some are so-so. Lots of fishing pressure in some of them. Others rarely see a human being.
I've never fished in that area in the fall. I am planning my weekend right now and might spend it there myself. If you see a little blue Honda ATV, say hello.
(Don't forget to try Ada's famous pies and her turkey dinners are to die for!!!)
he leases the lake but it's not private, the access by boat is what he can restrict you to, i've been fishing it both ways for a couple years with little luck, but i almost only go there when the fishing is bad everywhere else, and except when i rented the lodge, it was all shore fishing, which landed some specks and a small char but that was it. i've had lunch with him the last few times i was there, he gives lots of local info.
i rarely fish the lakes in that area now but used to 20 years ago. there are a couple others with "char" in them, not all from the same source.