During that time of year shore fishing on “the island” is pretty limited.
Most of the fishing activity is off shore, but it is always worth a shot.
The Ice road approach during low light periods may yield a fish if temps are right, the marina entrance may be another possibility.
Both of these locations are better early and late in the season, but brown trout show up from time to time.
The “lagoon” at the town park can yield some fun pike fishing from a canoe, they rent canoes and kayaks on the premise.
If the channel is open to the lake there is chance at a giant Lake Superior pike.
Let me know if you have any other questions. I used to work and live on madeline and stil get up there quite often.
I also have a friend who guides both lake trout and smallies from Madeline in his Ranger, If that is of any interest I’d be happy to share his contact info.
August is the best time of year to visit Madeline!