Horicon Marsh: galleryHoricon Marsh is one of the largest freshwater marshes in the United States. In the 1920s, at the urging of duck hunters, the state of Wisconsin established a State Wildlife Area that today includes 11,000 acres in the southern part of the marsh. In 1941 Horicon National Wildlife Refuge was established, at first largely because it was a critical nesting area for Redhead ducks. The federal refuge now protects the northern 22,000 acres. The marsh has since become an increasingly important resting and nesting place for many species of migratory waterfowl. More than 300 species of birds can be found at Horicon. In my visits during the last three years I have photographed only a few of these—taking pictures at Horicon is a continuing project...