Half of This Minnesota River Appears to Vanish Into a Hole

Drive up the northern shore of Lake Superior, and you eventually hit Judge C.R. Magney State Park. The Brule River runs heavily through this park, cutting straight through solid volcanic rock. About a mile and a half up the dirt trail, the river hits a huge ledge and splits perfectly in half around a piece of protruding rock.

A River Split In Two

The eastern side of the river does exactly what a waterfall should do. It drops 50 feet down into a wide pool and keeps flowing straight out to Lake Superior.

But the western half of the river does something completely different. It drops into a massive, dark hole in the rock called the Devil’s Kettle. And then, the water simply vanishes. For decades, people watched half a river pour directly into this pothole and never come back out. It looked like a glitch in the landscape.

Where Does The Water Go

The mystery bothered people for a long time. Locals and park rangers tried throwing everything they could find into the hole to see where it would pop up downstream. They threw in brightly colored dyes, ping pong balls, and even GPS trackers. None of it ever surfaced.

It seemed as if the water was vanishing deep underground. Some wondered if it traveled through hidden tunnels all the way to the bottom of Lake Superior. For years, no one could figure out how half a river could simply disappear.

Solving The Mystery

Geologists finally figured it out a few years ago. They started measuring the exact amount of water flowing in the river above the waterfall and compared it to the water flowing out below it.

The numbers were exactly the same. The water was not disappearing into the center of the earth. It turns out the pothole connects directly to the main plunge pool right below the falls. The water simply drops into the Kettle, hits a massive underground current, and gets pushed back up into the main river almost immediately.

The current at the bottom of the falls is so strong and violent that anything thrown into the hole is either pulverized or held deep by the water pressure. The ping pong balls never came up because the water just tore them apart. So the river never actually leaves its path; it just takes a very violent detour underground.