Comment by bombcar

Hence the statement "possession is 9/10ths of the law" - for the vast majority of property that people care about, you prove you're the owner by possessing it

Property tax is also the other 9/10ths - if someone is paying the property tax they're presumed to be the owner unless there's a court fight; and in fact, if you want, in many places in the USA you can get adverse possession by paying property tax on unknown or unwanted property - or buy them at auction by paying the back property tax.

The ones you can easily do this on are all various kinds and forms of worthless land, but hey, it's out there!