Never traveled the Canada side of Superior, but have done the Michigan side. As for things for the boys to do, if they like the outdoors then I would think they would enjoy it. Stop at the Soo locks, and they can watch the massive lake freighters travel through the locks just steps away. There is also an old laker turned into a museum that they can go on (museum ship Valley Camp). 50 miles south in St. Ignace is the Mackinaw Bridge, light house, Fort Michilamackinac (they have kids programs). They would love Castle Rock, basically a mountain they can climb and see the whole area. Very cool. West of the Soo is Tahquamenon Falls, very cool with hiking to the upper falls, and the surrounding area. Also Whitefish Point, a lighthouse/museum that is pretty interesting. And just 15 miles out lays the Edmund Fitzgerald. Just south of the falls is the Toonerville trolly and ferry ride through the Michigan wilderness, and Oswalds bear ranch. Young boys will love this, they can see up close many black bears. Largest all bear sanctuary in the US. Farther west in Munising they have a glass bottom boat tour where they float over shallow wrecks and you can see them through the bottom of the boat. Plus the beautiful Pictured Rocks shoreline. Traveling farther west through Marquette, L'Anse, Baraga, up in to Houghton/Hancock. Top of the hill (pretty respectable hill mind you) is the Quincy Mine. There are many mines in the Keweenaw Peninsula as this is copper country. A few of the mines give tours. Quincy has a very nice guided tour with tons of stuff around the property to interest young ones. Some mines let you wander on your own. At the tip of the Peninsula is Copper Harbor and Ft. Wilkins State park. the west side (new sites) are huge and you have Lake Superior in the back window and Lake Fanny Hooe in the front window. This state park is an historic site, with tours and demonstrations.
If you haven't noticed yet I do love the U.P. ;D So I guess I'm biased. The U.P. is covered in Forest, waterfalls, rivers, and lakes. And there are many, many campgrounds along the Superior coast, both state parks, forest camps, and private parks. Just a beautiful place.
Man, did I get carried away or what..... ;D