Abstract: Records, mainly 1923-1957, of the Wisconsin Division of the Izaak Walton League of America (IWL), a national organization that worked for clean water and the preservation of the natural environment. The records consist of officers’ correspondence, minutes, and administrative records. A majority of the records were created by Louis Radke, who was president of the Horicon Chapter, an early leader of the state organization, and a president of the Wisconsin Division for many years.