The 1,000-square-mile (640,900 acres) Upper Iowa River originates in Minnesota, but 78% of its watershed is in Northeast Iowa. The Upper Iowa River Watershed (UIRW) is part of the Driftless Region of Iowa. Its karst topography features limestone bluffs that rise 250 to 450 feet above the valley floor, dozens of coldwater trout streams, nearly 3,000 sinkholes and waterfalls, and hundreds of springs. Cropland accounts for more than 40% of the watershed, which also includes grassland (35%) and hardwood forests (19%). The EPA and Iowa recognize the UIRW as a Priority Watershed. Iowa designates 244 miles of the Upper Iowa River as High-quality Resource Waters or High-quality Waters, and the Upper Iowa was among the initial rivers included in the National Wild and Scenic River System.
The UIRW is a popular tourist destination. It has excellent walleye and bass fishing, but is best known for its 152 miles of coldwater trout steams, which lure anglers from around the world. More than 150 protected species of animals and plants live in the watershed, which also harbors endangered ecosystems. Unfortunately, frequent flooding and severe erosion are causing serious damage to the streams and rivers.