To the thread's OP:
Here's some of the CG in the U.P. which offer sites with full hookups. There are many more but this is a sampling scattered around the U.P. and near the Straits of Mackinac in the L.P.
Whispering Valley CG at Rapid River
Whitefish Hill RV park at Rapid River
Vagabond Resort near Escanaba
Gladstone Bay CG at Gladstone
Iron River RV Park & CG at Iron River
Marquette Tourist Park at Marquette
Gitche Gumee RV Park - E of Marquette
Perkins Park CG at Marquette
River Road RV Park CG at Ontanagon
Indian Lake Travel Resort at Manistique
Log Cabin Resort & CG at Curtis
Muniding Tourist Park CG at Munising
Wandering Wheels CG at Munising
Otter Lake CG - SW of Munising
Bay Mills Resort & Casino RV Park at Brimley
Castle Rock Lakefront CG at St Ignace
St Ignace/Mackinac Island KOA at St Ignace
Lakeshore Park CG at St Ignace
Tiki RV Park & CG at St Ignace
Mill Creek CG at Mackinaw City
There are a few thousand CG's total in the State of Michigan with a couple hundred thousand sites in total as RVing and camping is huge in the state. Michigan's been a travel and vacation destination for over a hundred years now and the numbers keeps growing as so many return year after year along with the many new ones. About 3/4 of the state's CG's are in the Lower Peninsula. Simply impossible to list them all on a forum!