Not until Zebulon Pike’s 1805 expedition was the only waterfall on the Mississippi technically surveyed at just over sixteen feet, about as high as an upended canoe. This natural wonder quickly became a scenic refuge for southern tourists escaping the summer heat. But money men were also scheming along the riverbanks, seeing only industrial power uncapitalized, and by 1870 the falls had been completely harnessed by the young city’s industrial pioneers. They had no notion that their seizure of the river’s power also halted a geologic process in its final moments.
The St. Anthony Falls of the seventeenth century—splendid, romantic, and terrible as they were to Dakota and Franciscan alike—were the faint echo of their cataclysmic origins just downstream from St. Paul. A dozen millennia ago, a surge of ice-age runoff first flooded over and eroded the stubborn Platteville limestone to create a cataract just as impressive as today’s Niagara Falls (another natural wonder first documented by Father Hennepin). Absent the ambitions and interventions of Minneapolis millers, the river would by now have eroded to the last reach of the Platteville limestone twelve miles from its start, and our legendary falls would have dissolved into a series of rapids through the underlying sandstone.
Even the newest residents of condominia overlooking this site should recognize St. Anthony Falls’ major components: the central spillway, or apron; the millpond fronting St. Anthony Main, which once powered a large share of the city’s industry but now generates a thread of the electricity we consume; and the boondoggle Upper St. Anthony Falls lock on the downtown side.
There’s a fourth component, however, that has for decades gone virtually unnoticed: The St. Anthony Falls Laboratory, a bastion of water-power research embedded in the middle of the river on Hennepin Island. Rampant nature created these falls, but engineers have preserved them, and so it is most fitting that the last significant use of the Falls of St. Anthony is a playground for engineers.
