I was looking into land access in the state of Maine, and I’m pretty sure it’s the only state with Implied consent to access non posted non developed land. This means essentially that as long as the land is not posted you can go on it to do non destructive activities, (eg Hiking, Walking a dog, even hunting) without express permission from the land owner, as long as you haven’t been trespassed or asked to leave. Don’t get me wrong you should always get permission but it’s not legally necessary.
There’s also a bit in there that you can’t prohibit access to a navigable body of water on your property, even if you own all the land around it.