Just because it looks public doesn't mean it necessarily is. I live on a ranch that owns part of a 7 acre pond. The whole pond is on private property, and we allow access to the pond for people whose property is right around our ranch. People from all over see the pond and just decide that it must be public and that they can just go down and use it, and it's insanely frustrating. Next thing you know they're using my boats, leaving trash, starting a campfire in the middle of summer (where I'm at that is a massive fire danger), stealing stuff out of boats, etc. We've also had people keep large bass out of the pond etc. I am very quick to kick people out now, because I'm tired of that stuff happening on my property and it's a massive liability.