sentences:  When River Warren Falls receded past the confluence of the much smaller Upper Mississippi River, a new waterfall was created where that river entered the much-lower River Warren.The new falls receded upstream on the Mississippi, migrating eight miles (13 km) over 9600 years to where Louis Hennepin first saw it and named St. Anthony Falls in 1680.Due to its value as a power source, this waterfall determined the location of Minneapolis.