Coldwater streams are best described as flowing waters with maximum summer water temperatures that are typically below 72 deg F. The watersheds of these streams are usually less than 100 square miles, and the streams exhibit mean annual flow rates of less than 50 cubic feet per second. Coldwater streams can be found statewide, contain relatively few fish species, and are dominated by trout and sculpins. The unglaciated Driftless Area in the state's southwestern corner exhibits a classically branched stream pattern and sharper, more eroded terrain. The rest of the state, smoothed by glaciers, has less topographic relief, creating sinuous streams with less average elevation drop.
