This is odd. Take a look at this map of America at night. As you'd expect, the cities are ablaze, the Great Lakes and the oceans dark, but if you look at the center, where the Eastern lights give way to the empty Western plains, there's a mysterious clump of light there that makes me wonder.
It's a little to the left, high up near the Canadian border. Just run your eye up that line of lights at the center of the country, look over to the upper left: There's a patch that looks like a big city — but there is no big city in that part of North Dakota. There's mostly grass. So what are those lights doing there? What is that?
If you need help, here's the same map again; this time, the patch is marked with a circle. It turns out, yes, that's not a city. And those lights weren't there six years ago.