Water has long shaped Decorah's history. The Winnebago and before them the Oneota fished the river, hunted mussels, and lived beside it, and the Oneota used ground clam shells to temper their pottery. Early settlers also depended on its power: William Painter built a mill at what is now Dunning's Spring, the William and Elizabeth Day family established their first campsite and log cabin above what became known as Day Spring, and Painter and Philip Morse built a dam on the Upper Iowa River and dug a millrace by hand to power Morse's saw mill and Painter's stone flouring mill. The river also powered the brick Woolen Mill, Tavener's Mill, and the Ice Cave Mill. North of W. Water Street, the flat area once called the Hitching Grounds served as Decorah's original parking area, where visitors tied wagons and horses along hitching rails by the millrace while they shopped, with footbridges at Court and River Streets connecting to the business district; the rails remained in use into the late 1920s. This area also held a sewer-covering dike, the city dump in the 1930s and 40s, and summer circuses, tent shows, and carnivals. Yet the river also brought repeated destruction, as spring and summer floods inundated lowlands, sent Dry Run into homes on Mechanic, River, and Mill Streets, covered parts of lower Winneshiek, Center, and Decorah Avenues, and destroyed tracks and bridges while causing property loss and deaths. The floods of 1902 were especially severe, with destructive flooding in May and again in June. From Decorah's founding in 1849, such flooding remained a recurring problem until city engineer Charles Altfillisch pursued a long campaign with city officials, the U.S. Army Corps of Engineers, and Congressmen Fred Biermann and Henry Talle to secure federal funding. In 1947, $1,245,000 was appropriated, work began at once, and by 1950 Dry Run had been diverted through the bluff at what is now Highway 52 into the river, the river bed had been altered, levees had been built, and the Bernatz Mill had been converted from water power to diesel power after elimination of the millrace. The project removed the regular flood threat and reclaimed broad areas of land for schools, public buildings, businesses, athletic fields, and Luther College facilities.