The North Shore of Minnesota features a unique natural phenomenon known as Devil’s Kettle Falls. Located near Grand Marais, the Brule River appears to swallow half of its water flow into a massive hole in the rock. This vanishing water fueled decades of speculation, challenging the understanding of local geology until recently.
Identifying the Devil’s Kettle Falls
The falls are situated within Judge C.R. Magney State Park, a rugged area along the north shore of Lake Superior. The Brule River encounters a prominent outcrop of hard, ancient rock, causing the stream to split into two cascades. One side plunges approximately fifty feet over the rock face in a visible waterfall. The other half of the river pours directly into a large, bowl-shaped pothole carved into the rock. This natural depression, the “kettle,” funnels the water into the earth, creating the visual effect of the river disappearing entirely.
Early Attempts to Solve the Mystery
Before modern scientific techniques, the fate of the missing water was a popular subject of local folklore and speculation. Theories ranged from the water traveling through a giant subterranean cavern to emerging many miles away at the bottom of Lake Superior. To test these ideas, curious visitors and researchers attempted to track the water’s path. Logs, brightly colored ping-pong balls, and dye were dropped into the churning kettle over the years. None of these objects ever resurfaced downstream, which deepened the enigma of the disappearing river.
The Geological Resolution
The true path of the water was revealed not by tracking objects, but by precisely measuring the river’s flow volume. Hydrologists from the Minnesota Department of Natural Resources used advanced stream-gauging equipment to compare the water volume above and below the falls. Measurements taken above the split showed the river flowing at a certain rate, while measurements taken several hundred feet downstream showed a nearly identical flow. For example, a flow of 123 cubic feet per second above the falls was matched by 121 cubic feet per second below.
This confirmed that no significant amount of water was leaving the river system, meaning the water pouring into the kettle must rejoin the main channel almost immediately. The hard, volcanic rhyolite bedrock contains fractures and fissures, likely created by a geological fault line. The rushing water has eroded a subterranean channel along one of these cracks, allowing it to bypass the main waterfall and quickly re-emerge underwater in the riverbed below.
Dropped objects never reappeared due to the immense power of the recirculating current within the plunge pool. This intense action simply disintegrates buoyant material or holds it under the surface until it is broken down.
Visiting Judge C.R. Magney State Park
Accessing the site requires visitors to hike a scenic, yet strenuous, trail within the state park. The route to the Devil’s Kettle is approximately 1.25 miles one way and involves navigating several flights of stairs, totaling over 200 steps. Visitors should remain on marked trails and always observe the viewing platforms to ensure safety. The strong currents and slippery rocks near the falls present a serious danger, and park officials caution against venturing close to the edge of the kettle itself.