Generally after the start of the trout season the Brule in MN fishes pretty good for Brook trout and some stocked Rainbows. The stretches below  Northern Lights Lake seem to produce better from what I heard. The area around Judge Magney is very steep and canyon conditions, there are nice deep pools and decent runs but the fly fishing has not been reported that great. As far as Steelhead and Coho, there is a good run later in the Steelhead season up the shore in that area, some seasons it can be fantastic!!! As far as other areas to fly fish, get a hold of a canoe or float tube and hit the inland lakes, they are the best in this area for Trout and Smallmouth!! And there are orther streams in that area that are fantastic. It is well worth the trip. Ice conditions will play an important part, so make sure you make some calls before you come up.  John at Great Lakes Fly Company.