Grandfather Falls, the Wisconsin River’s highest waterfall, descends 89 feet over about a mile of rocky cascade on exposed pre-Cambrian bedrock in northern Wisconsin. Long known as Konajewun, or “long falls,” it served Indigenous communities, fur traders, travelers, and lumbermen as both landmark and obstacle, with a major portage in use by 1851. In the logging era, the rapids hindered lumber rafting and helped create immense log jams. A small settlement grew after sawmilling development in 1880, then declined as railroads replaced river transport. Since 1938, much of the water has been diverted through a hydroelectric system that makes the site an important working power landscape.