You probably know that, for the most part, Yellowstone National Park is located in Wyoming. But there's a small sliver of the park that crosses the border into Idaho, and that tiny, 130-square-km (50-square-mile) patch is known as the Zone of Death.
Why? Well, thanks to a loophole in the US Constitution, you could technically get away with murder there.
As this Vox video explains, Yellowstone was established before the three states it occupies - Montana, Idaho, and Wyoming - joined the Union in 1872.
Because of this, it's different from all other federal land in the country, which is usually split up by its corresponding district courts.
Yellowstone, on the other hand, has been assigned fully to the District of Wyoming, as Michigan State law professor Brian Kalt points out in his 2005 paper, ominously titled, "The Perfect Crime."
So what happens if you were caught committing a murder in the Zone of Death? In other words, what would a court case look like if you were being tried for a crime by the District of Wyoming that you committed in the State of Idaho?
You'll probably be carted off to the courts of Cheyenne in Wyoming, but then you can point out that you should be tried in Idaho, seeing as that's where you committed the crime. So back to Idaho you'll go.
And here's where it gets tricky. Under the Sixth Amendment, the accused has the right to a jury composed of people from the state where the murder was committed (Idaho) and from the federal district where it was committed (Wyoming).
But that doesn't mean anyone from Idaho and Wyoming, it means people living in the area where the crime was committed.
This could be possible for the Wyoming portion of the park, because around 2,000 people actually live there, and if you committed murder in the sliver of park in Montana, you'd be in trouble, because people live there too.
But not a single person lives in the 130-square-km patch of Yellowstone in Idaho.
So, as Kalt says, "[T]he loophole looms, waiting for a murderer to exploit it. I feel like I've done what I can to prevent this; the blood will be on the government's hands."
But, you know, if you're a mother-in-law, ex-boyfriend, or fiendish banker, it's on you for accepting a picnic invite to the Zone of Death, right?
A version of this article was first published in November 2016.