Hi rookie and welcome to the forums!
It's been a quite a few years since I've been up the shore chasing trout ever since doing more warm water species, but I can try to dig into the old brain and try to remember something.
I did alot of fishing up the shore for brook and rainbow. I would not get to discouraged of not catching to many brook trout on the lower sections of most of the North Shore streams. Years of washout and the fact that almost all of the North Shore streams have rainwater as their may source of water flow and generally not having the big streams to be able to sustain big populations of brook trout. Don't get me wrong there are plenty of trout to be caught, but not like true spring fed streams. Northshore streams, especially the upper sections use shade and current to keep the water cool to what brook trout like. So your deeper pools and shaded deeper areas will have some good trout fishing action, along brushy/tree banks are good.
I've fished the Temperance River with my grand pa a few times and had a good time. But I remember going outside of the park area going north of course. I know we took a road near Tofte, went North and there were some back roads that crossed the river and some other hiking/fishing trails going along the river. Like I said, been awhile.
We basically fished pocket water....all the deeper pools and anywhere where the water would be cooled and have plenty of O2, turbelence, and the fish had some cover to hide. You could be fishing a little picket that was 2'x2', but a foot hole in the middle with a big enuf rock for a trout to hide under and dable a nymph right thru the little pool and they will come out to play .
This is what I used mostly. You can get some prince nymphs and/or Pass Lakes (a little harder to find in shops) for wet fly/small streamer fishing. Fishing it cross current and retrieving slowly, awesome is slower deeper sections of NS rivers. Dry flys like the Wulff stimulators in size 10, give them something they can't pass up and of course Elk Hair Caddis and Adams. Nymphing has always been my favorite way to fly fish for trout. I like to use a caddis larvae imitation or Pheasant tail. I would add a small splitshot about 6-8 inches up from the fly and add a strike indicator. You would need to adjust the indicator so the splitshot is ticking the bottom. Beside the deeper runs, it works great for dabbling the smaller deeper pocket water.
Remember that there are anglers that only fish the hard to reach brook streams and lesser known areas of the North Shore and do very well with some big brook trout to be caught out there. But it's takes alot of searching and once you find a gem, you pretty much keep it to your self, thats why you don't see many people spread the work about their secret brook trout streams. Small NS streams just can't take the punishment of many anglers.
Alright enuf of my rambling, good luck out there and tell how you do next time your out!
Oh, almost forgot. Call John at 218-740-3040 who owns Great Lakes Fly Company, a fly shop in Downtown Duluth, MN. Tell him TheFlyMaster said hi!