old dude: I >think< that if you have to pay for entry and you don't pay, they can kick you out / call it trespassing, anywhere. (I have no idea what the rules are about being arrested for trespass - and here it would be an Alaska question.) However, if the property is generally open to all comers, and somebody kicks one or a group out, in Colorado/California/New Jersey/North Dakota (Pennsylvania?), the aggrieved can say "you were unreasonably stifling my free speech as your true or main or only possible intent." So he/they could sue in one of those states or one of the undeclared (or particularly ambiguous) states (like Alaska) and find out how the state judges want to play it - under their own state constitution as constrained by the US Bill of Rights.

Good question about what he was arrested for.