The St. Croix River

The St. Croix River. . , Look out at the top of the bluffs. Now look down to the river. That height difference represents the power of the St. Croix River. Over the past 15,000 years, the river has carved out this valley., Nature isn't the only force making changes in the river. During the logging era, people built rock and timber islands to break ice before it reached Nevers Dam. Today, these islands create a refuge for aquatic species like small-mouth bass and basking map turtles., Always Changing , Rivers constantly change. As they rise, fall, and shift, they transform the surrounding landscape., Some changes, like flash floods, alter the river's character overnight. Others are more gradual. Where water moves quickly, it erodes the shoreline. Where it moves more slowly, it drops sediments and creates sandbars., Many species are attuned to these changes. Some shoreline trees disperse their seeds in the water. Trees located on sandbar islands are important habitat for nesting herons. The river's swift-moving current means some spots remain ice-free all winter, the open water attracts hundreds of trumpeter swans.