The Platte River Campground is certainly nice, but a bit difficult to get into. The other campground within the park is D.H. Day campground, but it is considered a rustic CG, although a portion of it does allow generators. It has a great beach though and is just south of Glen Arbor. I believe they do not accept reservations for D.H. Day so get there early if you want a site.
For private campgrounds I would suggest Indigo Bluffs located on M-72 east of Empire about 5-7 miles. We stayed in the RV portion of the park last summer and found it nice enough. It has water & electric, but there are just a few FHU sites. The motorhome portion of the park is mostly privately owned sites and is right next to the RV park. Chances of getting into the RV portion are fairly good, but reservations might be a good idea. RV Park Reviews.com link below.
http://www.rvparkreviews.com/regions/Michigan/Empire.htmlFurther south of this area you will find a nice campground on the north side of Manistee at Little River Casino. There is also a nice state park in Manistee called Orchard Beach State Park. There are openings there right now because I just checked the state reservation system yesterday for July dates. Traveling M-22 north from Manistee is a nice drive all the way up to Leland and Northport.
