Why do only some campgrounds offer reservations?

If the campground offers reservations through its website or via email, we provide the best possible mechanism ... website, email or phone.  Some campgrounds do not have reservation options that we have access to. We welcome user information with information on reservations at a particular campground. To help us update reservations, locate the orange "Suggest an Edit" button at the bottom of every campground card and follow the prompts.