Kelley’s Island State Park Campground
First notes... you have to take a ferry to the camp ground. Kelley’s Island Ferry in Marblehead. It is a few miles to camp ground so if you are renting and don’t bring a vehicle you will want to rent a golf cart. You can bring a car to the island.
The camp ground is away from the downtown(think small) a few restaurants and a general store and market.
Now for the campground. It is great right on Lake Erie. Most space have at least one tree. The tent only area has lots of shade. The bathrooms are relatively clean. The folks who oversee are actively there working on things. Cleaning marking reserved spots. You can reserve a spot ahead and I would absolutely do that during season. The island has space to launch kayaks a boat dock. Plenty of hiking bring your bike to see the whole thing via peddle power. There is a brewery and winery.