I disagree with the poster about wasting money on improvements. I think habitat improvements are the main thing that have brought the trout fishery in our state to what it is now and that is in some cases a "destination fishery" for people that want to travel and its also listed in the 50 places to fly fish before you die.
I currently live in vilas county and just before this year I lived in the driftless so I still regularly fish both areas.
The fact of the matter is that northern wisconsin simply does not have the appropriate gradient in many of the streams to have them very trout friendly. Along with the lack of gradient comes environmental change, climate warming, a few years of drought, hard winters, over fishing, over farming etc and there goes your trout habitat.
Even many of the blue ribbon level streams in the UP are TOO warm to fish in the middle of summer because they are not cold water fisheries like we have in the driftless region.
That being said I have caught plenty of brook trout, brown trout, and rainbow trout in the north woods so far this year but I now concentrate on the upper peninsula because it is just as short of a drive to some of the better streams than some of the wisconsin ones around me.
Last week I got into some pretty consistent nice brown trout fishing mostly dry dropper patterns --- had to downsize the dry to get hit --- tan caddis for some reason was working with a small hatch going on and a flashy little thin bodied nymph was getting the majority of the hits. Some of the best advice I have gotten trout fishing is to carry a thermometer with. There are some streams that not only aren't worth fishing with certain warmer temps but ones that you SHOULDNT fish at a certain point if you hope to revive any of the trout you catch.