Summary
At Devil's Kettle in northern Minnesota, the Brule River splits around a mass of volcanic rock. One branch drops approximately 50 feet into a pool, while the other plunges into a deep pothole and appears to disappear underground. For decades, the destination of the missing water remained a geological mystery, reinforced by reports that sticks and other objects thrown into the Kettle were never seen emerging downstream. Flow measurements conducted by the Minnesota Department of Natural Resources in 2016 showed that virtually no water was being lost: the water entering Devil's Kettle resurges into the Brule River downstream. The central mystery is therefore considered solved.
Additional Notes
Devil's Kettle is located on the Brule River in Judge C. R. Magney State Park near Grand Marais, Minnesota. At the falls, the river divides around an outcrop of hard volcanic rock. The eastern branch drops approximately 50 feet into a visible pool, while the western branch plunges into a large pothole and disappears from view. For decades, no obvious outlet could be identified, leading to speculation that the water entered a hidden underground passage or travelled separately toward Lake Superior. Visitors also contributed to the mystery by throwing sticks and other buoyant objects into the Kettle. These objects were reportedly not seen emerging downstream. Geologists nevertheless considered a long underground route unlikely because the surrounding rhyolite and basalt are not the types of rock in which extensive solution channels normally develop. In late 2016, hydrologists from the Minnesota Department of Natural Resources tested a simpler possibility: that the water was returning to the Brule River almost immediately downstream. They measured a flow of approximately 123 cubic feet per second above Devil's Kettle and 121 cubic feet per second several hundred feet below it. The difference was within the tolerance of the measuring equipment, demonstrating that essentially no water was missing from the river system. The failure of thrown objects to reappear does not require a hidden outlet. Researchers explained that the powerful recirculating currents inside the plunge pool can trap floating material, break it apart and keep it submerged before fragments eventually continue downstream. The measurements therefore resolved the central mystery: the water entering Devil's Kettle does not disappear into an unknown underground system but rejoins the Brule River below the falls.
The Location Today
Devil's Kettle is a waterfall on the Brule River within Judge C. R. Magney State Park in Minnesota. Visitors can reach a designated overlook via a steep, rocky hiking trail with many stairs; vehicle permits and park regulations apply.
- Environment
- River, Waterfall
- Time of Day
- Various times of the day
- Evidence Level
- Investigated Case
- Visiting the Location
- Limited
- Ownership of the Location
- Public