I have determined that Lander WY is the friendliest city in America... plus, they let you camp for FREE up to three nights in their city (town) park. There are restrooms with flushing toilets and running water. Nice soft green grass to set your tent up in. I recommend getting a burger from the Lander Bar when you visit!

There are picnic shelters, horseshoe pits and lots of trees.

And sprinklers... be aware, you might get a wet tent (see video)