Imagine yourself (if you can) on an Alaska moose hunting trip riding along in your hovercraft. Oh no your hovercraft has just broken down! While you are repairing it, three National Park Service (NPS) law enforcement officers inform you that you cannot operate it here because of an NPS regulation banning hovercrafts.
You are shocked because you know that while the portion of the Nation River you are on is contained in a national park, Alaska owns (at least) the land under the Nation River.
So what would you do? John Sturgeon sued.