A primitive campground without drinking water or electricity. Fires are not allowed. There is is space for RVs and horses. It is a national park so check on pet regulations.
The upside, Buffalo can wander through your camp. Or pose in the prairie next to the camp. Great hikes into the park.
Oh, all the things they say about being careful around buffalo, they mean it. I saw a couple who walked too close to a buffalo. Lucky for them the startled animal went away but they were in serious danger.