Breitenbush is a retreat center that offers a variety of different accommodation options including cabins, lodge rooms, dorms, platform tents, and campsites for tents only and tents with cars. 

The tent sites (for your own tent or the platform tents) are only available in the summer.

Camping (or staying in any of the accommodation options) at Breitenbush is part of a package deal. For a tent you pay $77 a day for one person, which includes your entrance to the hotspring as well as 3 meals and your participation in any activities that are happening while you are there (like yoga or meditation).

The campground is really basic- basically just a space for your tent in and it's a short walk in from the parking lot. Carts are provided.  There are 5 sites you can reserve that have space for a vehicle.

There are lots of rules - no stoves, no alcohol, no food in the camp area, etc. But really everything you need is provided for you at the mealtimes in the lodge, so it's more like you sleep in your tent vs. being around your tent for a camping experience.

The hotsprings are amazing (and clothing optional- and most people are opting out), and there is some decent hiking to do that is accessible from the trailhead at the Breitenbush parking lot. 

You can also access the hotsprings by reserving a day pass (call ahead from Detroit - there's no signal past the 46 turnoff).  Another option is to camp at one of the nearby campsites and daypass the hotsprings if you aren't into dining at the retreat center option.

It's a great place. It got 4 stars instead of 5 because it isn't really an amazing campground. Also- the nearest campground toilets are  port a potties. There is a bathhouse and showers available near the cabins, but you'll have to walk.