3rd week of july will be fine plus. CG's: ots of them both State Parks etc and private owned all over the U.P. and the L.P. We live in West Michigan on Lake Michigan in the L.P. and go up to the U.P. a lot in all seasons. Every year one or more times in our 57years of marriage and the black flies issues are so overblown. Yes they can be a problem for 2-3 weeks in June but that's about it.
Our Favorite CG's are Tahquamenon State Park Lower Falls CG (Portage CG) as so much to see and do in the area. Close the the Great Lakes Shipwreck Museum at Whitefish Point. Very popular.
A little north of Tahquamenon Falls there's Muskallonge Lake State Park on Lake Superior and Muskallonge Lake.
Aune-Osborn at the Soo Locks (the worlds bussiest locks with even 1000' ships going thru and they go 100-300 yards away from you either at the locks or the CG).
Fayette Historic State Park on the Garden Peninsula, Has the gorgeous Snail Shell Harbor and the restored iron works many building.
Indian Lake State Park CG and Kitch-iti-kipi Palms Book State Park is close by but has no camping right there. Very interesting huge spring you human power the ferry across the crystal clear deep spring. 10,000 gallons every minute flow and lots of large fish always in view in the super clear water which is a constant 45 degrees year around.
Munising Tourist Park CG with lots views. Remember that Lake Superior is always cold even in summer as it's so huge and deep and far north. A quick dip is about all one can take in the very clear clean waters.
These are our favorites up there among many others. Michigan has over a hundred
State Parks and thousands of campgrounds. More than 11,000 inland lakes alone and more than 3,200 miles of Great Lake's shorelines on 4 of the 5 vast Great Lakes. No place you can stand in the entire state and be more than 6 miles from a lake.
Lots of Privately owned CG all over the U.P. Far too many to list.
Not too many CG's have full hookups in the U.P. but have electric, water, and dump stations at most all and have good clean bath houses/restrooms. That's why/what RV's have holding tanks for.