Munising Tourist Park, (906) 387-3145, E8518 W M-28 West, Munising, Michigan 49862
https://munisingtouristpark.com/ There are spaces right on Lake Superior (15' from the beach) with full hookups, but without reservations, they are very hard to get. The campground is just west of Munising, about 3 miles from the boat dock for the shipwreck and Pictured Rocks boat cruises. Don't forget to go to Muldoon's Pasties for lunch and the Apple Pastie is "to die for" as dessert.
Marquette Tourist Park, (906) 228 0465, Sugarloaf Ave, Marquette, MI 49855
http://www.mqtcty.org/parks-tourist.php Tourist Park has spaces with 30/50 amps and many are long enough to handle a 40' RV. Don't forget your water regulator, the water pressure there is "high enough to cause damage" !!!!!
There are other campgrounds further west of Marquette, but they aren't as convenient as the Tourist Park.
Use caution if you consider Gitchee Goomee Campground on M28. There are a number of negative reviews. Do your research before making reservations there......
http://www.gitchegumeepark.com/home.html
Have fun, We are in and out of the UP all summer long. If you need any information, post here or send me a PM.