The Minnesota River follows the path of the Glacial River Warren. The valley is a hydrologically dynamic system cut through glacial sediments deposited by the Des Moines Lobe of the Laurentide ice sheet. From west to east across the basin precipitation increases while total dissolved solids, sulfates and trace element boron decrease. Upland storage has been decreased during the past century through the use of tiling and ditches. This decrease is believed to result in lower numbers of wetland acres and accelerated movement of soil and dissolved minerals to the river and its tributaries.