Six Mile Cypress Slough Preserve in Fort Myers, Florida, is a 3,500-acre wetland that protects a nine-mile slough and forms part of a larger 57-square-mile watershed feeding Estero Bay. The preserve filters and stores water, helps control flooding, and provides a wildlife corridor for plants and animals, including endangered species and migratory birds along the Atlantic Flyway. Public access is centered on a boardwalk, interpretive center, and amphitheater designed to limit harm to the habitat. Its preservation grew from local activism in the 1970s, when the Monday Group, a Fort Myers high school environmental class, helped win support for protecting the slough.