The mystery of the Devil's Kettle—a geological anomaly in Minnesota where half of the Brule River vanishes into a stone pothole—was officially "found" or solved by the Minnesota Department of Natural Resources (DNR) in 2017. For decades, locals and tourists speculated that the water led to another dimension or an underground cave system, but hydrologists Jeff Green and Calvin Alexander used a scientific approach to find the answer. By measuring the water's flow rate both above the falls and several hundred feet downstream, they discovered that the volume was nearly identical (roughly 123 cubic feet per second). This proved that the water plunging into the "Kettle" doesn't disappear; it simply rejoins the main river almost immediately through underground fissures in the rock. While they planned to use a biodegradable fluorescent dye to visually confirm the exact exit point, the mathematical evidence of the "resurgence" was enough to debunk the myths that had surrounded the site since the park's founding.