Where are folks finding all of these "pets NOT welcome" places? In all my travels I've found only one place that stated 'no pets' and that was one small section (about 10 sites out of 300) of a huge COE campground.
Skipnchar: There are a number of parks in Pennsylvania and New Jersey that do not allow dogs at all. And some that do are anything but "pet friendly." Example: a KOA in the Delaware Water Gap (PA) where you are yelled at by management if you walk your dog (on leash) outside of your site. I was told that I should "carry" my Welsh Terrier to the "exercise area" , which by-the-way is about the size of a large bread box. I put Dilsea in this thing and she thought she was a gerbil!
Dilsea is about as friendly as a dog can be and weighs 20 lbs.