Decades of agriculture and urban development have severely degraded the natural ecosystem of Willow Creek, a rare cold-water system that supports reproducing migratory species of salmon and trout. Because of the Willow Creek Preserve’s importance as an Area of Special Natural Resource Interest within the Sheboygan River, the Glacial Lake Conservancy is working to restore it by removing two culverts that obstruct the passage of these fish species, revegetating the area, and creating a detailed Land Management Plan.