It is true that all rivers ultimately flow into a larger water body. But it seems that this fact doesn’t hold right in the case of the Devil’s Kettle waterfalls in Minnesota.
We know that Brule is not a drain and Superior is a lake. Then what is the cause of double waterfall?
"All drains lead to the ocean" doesn't seem true in case of the Devil's Kettle waterfalls.
Located by Lake Superior's northern coast, where the Brule River forks in Judge C.R. Magney State Park in Grand Marais, lies an environmental irregularity.
The Devil's Kettle is a huge crater that endlessly swallows half the water of Brule, yet no one has ever found out where the water goes.
Some theories have proposed that such condition has resulted due to tectonic action or a lava tube. But there are no fault lines and lava tubes in the area. So the question remains that where does the other half of the water and all the objects that were thrown into the Kettle go?
Larger debris such as rocks and trees has also dropped in the cascades during the storms but none of them was recovered. It seems that whatever is thrown into the Kettle disappears forever.