Two, I think; can you name any others? - the claims, I mean, that governments make and which they say secure their proper position as rulers in a country.
One is that they have rightful dominion in a certain geographic area, inside its borders. A neat name for such an area is a "tax farm", but it's not one used by government people. Moo-ch too revealing.
The second is that they have rightful dominion over the people who live in it; that those people can do whatever they wish but only within limits set by the government. This goes together with the first, in a perfect blend. The particular rules imposed vary by time and place, and include rules about leaving the one tax farm and moving to another, but whatever laws are written, are said to be right and proper. If you wonder how one rule can be "right" on one side of a border but "wrong" on the other, join the club.
Upon what do these two claims rest?
In a single word: sand. So there is a good point upon which to challenge those who suppose and assert that whatever is, is right. Let's take each in turn.
The alleged right to control what happens within a certain land area is usually called "ownership" and so Claim #1 above is that the government of some area at some time is a claim that it owns the land. How, then, is land ownership properly acquired?
Clearly and properly, it can be acquired by voluntary transfer of title by the previous owner, as is the case with any other kind of property. So the main thing we need check is that the original title was valid. There's the rub; it's not too easy to define that, rationally and ethically.
An original title to land is by definition obtained (somehow) when the land is still unclaimed wilderness not owned by anyone else. Up to that moment, nobody has wanted it. Then someone perceives a use for it, and so wishes to take control, to be its owner. How?
The only rational way I know is that of John Locke. He suggested a claim to own land became valid when the claimant worked it, or "mixed his labor with the soil." Elegantly, that sets a limit on claims; if you stake out an area too big for you to work, it's not truly yours. Others may arrive and make neighboring claims, and the Lockean principle is well suited to be used in settlement of any disagreements.
Notably, grand, monarchical, governmental claims to vast unexplored areas of land are therefore void. They are far too large to be worked, and in fact the governments making the claims do not work them; the most they do is to grant charters to some other people to work them, as if that granting somehow validates the claim. It does not; if the claim to own land is bogus, the "grant" to rent it is likewise void.
Accordingly, the British claim to the English colonies was void, and when in 1783 they were ceded to the new States, that transfer too was vacuous; nobody can validly hand over something he doesn't own. Hence no government owns any land in America; Claim #1 above, to have dominion over a certain area with geographic borders as a "tax farm", is flatulent.
The second claim governments make is to have dominion over people, living in the alleged domain. Usually this Claim #2 is not comprehensive - those people are not 100% enslaved - the control (claimed ownership) is partial. Even so, this flatly contradicts the Self Ownership Axiom; since axioms can not be refuted, that claim too is bogus.
With what, then are we left? - a set of people who call themselves the "government" and make grandoise but unsubstantiated claims to own and operate certain swaths of land and to control the people residing in them. They are quite entitled to their opinion to that effect; they are not entitled to impose those opinions on anyone else. They do so anyway, thereby classing themselves as gangs of thugs. They have no more right or power than that which derives from might; as one of them said, more frankly than most, "power comes from the barrel of a gun."
I don't often see this simple and adequate argument against government used, and that's a pity. It nicely cuts all the ground from under them, and deserves wider exposure. If you agree, help it on its way! It applies not just with respect to State and Federal claims to "park" land - reservations on which no regular building can be erected without special permission, seldom granted - but to every square inch of America, and other countries respectively. This is easy to verify; look at the title deed to your "own" real estate, and notice in the small print that your right to control it is contingent on the permission of one or more of the levels of government. There is no private ownership of land!
This ugly fact will complicate the transition to a zero government society. It should be fairly easy to adjust the title of most lots; if you've been living on a couple of acres which you bought in good faith, title companies are likely to recognize your claim to true ownership - but even then, contrary claims will have to be entertained and settled. With regard to State and National Parks, no such precedent applies and Lockean claims to be the first claimant to work portions of the land will need to be recorded. The same will be true of other real estate "owned" by government, including offices, trash dumps (but I repeat myself), military bases etc ad nauseam. It will be whole bunch of fun.