I stayed at the campsite nearest to where the ferry drops you off. There were several sites to choose from, and we were able to snag a spot with a small trail to Lake Michigan. There was a fire pit with a grill, and an out house style bathroom a short walk away. We hung our food to keep the chipmunks out of it- they did chew on my sunglasses case that I left out!

Hiking trails on the island are well marked, and fairly easy. I would recommend staying 2 nights if you want to see the whole island, though. With the ferry schedule, you wouldn't have time to see everything. I'd also recommend bringing more food than you think you need, in case the weather turns and the ferry can't pick you up on the day planned.